I don't think we can expect people who are deeply invested in CA to just switch and be okay with ZA. The dynamic is different, and we have no idea how SE is going to portray it in part 3.
I hope this doesn't feel like I'm singling you out but this bothered me a bit because I think these kinds of phrases contribute to muddying and perpetuating debates about shipping (which is kind of what LTDs are about, at their core). So my apologies in advance but I'll use your comment as a springboard.
The thing is, whether people are deeply invested in CA or not, they have no reason or obligation to "switch" or even be okay with ZA. Both of those are purely subjective. No one is trying to "convert" others out of shipping their ship, whether they like them for their dynamic or aesthetics or whatever else.
The LTDs are usually about: stop lying about canon. Like, that's basically it, lol. People don't have to stop having fun with fanon, headcanons, and stuff they plain made up but that should be left to the realm of fan fics instead of discussions of what's actually in the text. People can ship CA, they can dislike ZA (which also applies the other way around, of course), but stop lying about their canonicity, lol. And you know, stop the harassment of creators and other fans, etc etc etc. Shipping is supposed to be fun, not a cult.
Of course, this is kind of simplified because there are a lot of factors that go into shipping and these discourses. But at their core these debates perpetuate because one side seems to think it's about shipping while the other side is just telling them to stop (intentionally or not) lying about the source material.