I don't think Heidi really gave a shit about that cape, she just saw it as an easy few grand* for her to splurge on more shitass dresses for herself. (*$130 a pop, she wants 30, so she's expecting to get $3,900 for a cape that doesn't really pair with many outfits all that well.) I think she only wore the sample one once for a promotional picture, and once she posted it for sale, she basically forgot about it.
I mean, most of her recent campaigns involved her ignoring them until the last day or two, so I'm not surprised about her not advertising it at all. You do have a point about her not wearing the prototype, even when she wasn't actively advertising her other campaigns she at least wore the prototype for it everywhere she went, that part is actually a change in her usual store promotion routine.
