Indigo

first, in this variety interview sarah schechter (series producer & chair of the main production company) is quoted as saying: "i mean, that's, like, too hot for tv. i dont think there was a reason for it. i think there's a fantastic, fantastic amount of lgbtq representation on the show"

second: in this tvline article from about 2 months later, roberto aguirre-sacasa (showrunner of riverdale) is quoted as saying: "we hadnt even really laid even the barest seed of there being a romance between archie and jughead. not even a whisper of that... we hadn't really explored or even hinted at that, where we had with all the other couplings. (...) it was just like, 'is this a cheat if we do this?'"

so obviously irrespective of anything else a grain of salt is due, i dont think the veracity of statements made for press interviews is a given: the press interview is a specific context where speech has a specific purpose lol. schechter's answer in particular is a essentially a pr-inflected dismissal of the question (she also seems to be reading the topic as a matter of "whether or not there is queer representation in the show", which is pretty clearly beside the point).

aguirre-sacasa's statement is more interesting. like i said, it's literally not possible for the omission of jarchie (archhead?) from the finale to be literally anything other than a conscious decision, & aguirre-sacasa is directly acknowledging that here in unambiguous terms. more to the point though i find rationalizing the elision in terms of foreshadowing & setup kind of suspect for several reasons. most obviously: it is true that jarchie did not get as much foreshadowing as beronica (vetty?), but that's a somewhat moot point considering b/v only started getting substance within the final season. prior to that the only nugget was their kiss in the pilot episode (which was both diegetically & irl a non-romantic play for attention with no lasting significance), plus arguably the very brief moment in s6 where betty questions her sexuality. prior to s7 betty/veronica was no more substantiated than veronica/cheryl, or archie/kevin, neither of which featured in the final season. so if betty/veronica get to have a finale confirmation in The Quad Montage solely based on the amount of time season 7 spends teasing them, the question has to be: why not spend any time in season 7 teasing archie/jughead? if the quad was pre-planned then surely it wouldve been possible to do so (necessary, even, if we are to operate by aguirre-sacasa's avowed logic here)

ill grant that from season 3 onward, the production of the later episodes in each season overlapped with the airing of earlier ones, and as far as i can tell there's no publicly available documentation of when in that cycle scripts were being written: it's therefore impossible to rule out the possibility that the polycule idea truly only manifested late enough in s7's production for any jarchie foreshadowing to be genuinely out of the question. but even if that's true, i dont think it's half as weighty as aguirre-sacasa is construing it, because i dont accept the fundamental logic of his claims for two reasons

first: ok. archie/jughead hasnt been foreshadowed outside of one brief line in season 2 where the idea that they could someday kiss is playfully teased (which, again, is really not that much less than what betty/veronica had prior to season 7). but what *has* been foreshadowed (at length!) is the idea of archie being attracted to men. even if you disregard his entire thing with hiram in season 2, season 7 makes it explicit that archie is questioning his sexuality, depicts him getting turned on by gay porn & being perturbed when people around him invoke gayness as an insult, and teases the potential of something happening between archie & reggie. in light of that, and given the gestures the series has made toward the strength of archie & jughead's bond, i dont feel that there's insignificant support for giving the two of them an overt pairing in the finale: at maximum one or two explanatory lines would be required.

second: even supposing the last paragraph isnt good enough... when has riverdale ever cared about what has or has not been set up? a friend of mine has an adage that "each episode's writer isnt allowed to know about anything that happened more than one episode earlier". season 4 cliffhangs kevin running afoul of a dangerous underground ring of tickle fetish videographers (i swear to god i didnt make that up), & it's literally never acknowledged again. a few episodes before the finale we learn that ethel has entered a relationship entirely offscreen & is moving across the country with him. season 6 convolutes a reason why veronica & cheryl have to make out to save the world, complete with a brief-yet-grating debate about queerbaiting. the toni/jughead flirtation in season 2 deflates unceremoniously & at a lightning pace. fangs/kevin was teased before going unacknowledged for several episodes before the reveal that fangs/midge had been happening at length offscreen. most of kevin's relationships manifest out of thin air. bughead, one of riverdale's first major couples, was predicated on essentially nothing! saying that archie & jughead hooked up at some point during a 1-year timeskip would in fact be "cheating" less than several of the show's romances!

further to that: riverdale spent its entire run making plenty of decisions on the basis of shock factor or wow factor (including, let's be honest with ourselves, the polycule plot beat itself), & even (or especially?) in the absence of buildup, a jarchie confirmation in the series finale would more than qualify. imagine the screenrant headlines lol. in fact, aguirre-sacasa remarks, as quoted right after in the same article: "when I look back, wouldn't it have been great to just pop to kj and cole kissing? (...) i think everyone would've been up for it. i think cole and kj would've completely been up for it. who doesn't want to see that?"

so in light of everything, i just dont think 'we consciously chose to omit only one of the six possible pairings in a four-character polycule, fully aware that that omission would be glaringly obvious & unmistakably deliberate, because there wasnt sufficient buildup for that pairing' is particularly convincing as a recounting of a line of reasoning. obviously i cant prove that beyond doubt (& any speculation as to "an actual reason" would amount to theoretical guesswork), but my suspicion is that aguirre-sacasa's statement is either an optimized pr line or an effort to rationalize (willfully or unconsciously, ad hoc or premeditated) something that played out at least slightly differently