TBH I really think a lot of the age discourse regarding Akuroku was fans trying to rationalize Axel's very extreme friendship with Roxas. Before BBS confirmed Axel's age, people looked at their dynamic in KH2 and collectively thought, "well, he LOOKS like an adult. But he is very Not Normal about this teenager. So he's PROBABLY younger than he looks".
If Axel had been a full-blown villain in KH2, or if his dynamic with Roxas was portrayed negatively rather than sympathetically, then people probably would've gotten pedo vibes from it and correctly identified him as an adult. But because he was an anti-villain who the narrative frames as just wanting his friend back... because we're so clearly meant to CARE ABOUT and root for this relationship... it complicates things.
The thing is it's WEIRD for a roughly 15 year old to be besties with a grown ass man. Age gap friendships do exist, but typically much later in life. It's incredibly rare for a teenager to be so close with someone a decade plus older than than. To the point most people would immediately assume something predatory is happening. So yeah, before BBS clarified that Axel WAS significantly older than Roxas, I think it makes sense people assumed he was at most a few years older. If anything it's a charitable assumption that makes Axel look much less like a creep. Since the story wants you to care about their friendship and it would be weird-verging-on-uncomfortable if he's so much older... "clearly" Axel must be close in age to Roxas.
Their relationship is given the same kind of writing and significance as Sora, Riku, and Kairi, who ARE all within two years of each other. But logically Axel's dynamic with Roxas should be very different if they have an extreme age gap. The fact that it was presented so similarly to Sorikai (and even Days continued this, since adding Xion to the mix just further solidified parallels between the two trios) surely contributed to the misunderstanding.
I think this is also why now most of the fandom has pivoted to family-zoning Akuroku. Axel is either Roxas' older brother figure, or even a father figure. Despite that not reflecting their interactions and dynamic in canon. It's because deep down, We All Know. Their friendship with the age gap is weird. It immediately rings subconscious alarm bells about Axel's intentions. So now that we KNOW Axel's age and shipping him with Roxas is unsavory, fans had to go in the extreme opposite direction from romance to find another reason for his slightly obsessive devotion to Roxas.
I feel bad for the diehard Akuroku fans. Most if not all got into the ship at a time when they interpreted the pair as much closer in age. The ship wasn't problematic until later games made it so. It's a shame that so many people get harassed for holding onto a pairing that was near and dear to them for several years and was NEVER predatory in their eyes. As long as everyone properly tags and warns for the content they create, I don't see why we can't all leave each other alone. Enjoy the stuff you're into, block the stuff you're not. But trying to criticize and censor a fictional pairing out of existence doesn't actually help anything in reality. It just hurts the real people who DO like the ship.