Conceptually, Zootopia would be much further along. It's a clone of the attraction already in the late stages of construction at Shanghai Disneyland and scheduled to open before the end of the year over there. It would also be a replacement for Dinosaur, likely reusing the existing show building. So construction could theoretically be a lot quicker than the Moana attraction. Unless they intentionally delay its construction and build Moana first. Incidentally, there have been cases of some of the Asian parks having contracts preventing some of their newly built rides being cloned elsewhere for a certain period of time after. I think this was the case for Tron initially. I'm not sure if Zootopia has one though. If it does, that could delay it.
For what it's worth however, i'm not sure any of the AK projects are going to take priority at WDW. Despite seeming like it would come first. Take with a grain of salt, but the Magic Kingdom projects might actually happen first per a rumor I heard about what WDI allegedly wants to do. Even though that stuff looked earlier in development. Depends on whatever corporate wants to happen though.
I'm actually not expecting to see either of these projects at this event though. It's D23 proper that they use to make major announcements, this event is for lesser projects or things already pretty far in the development process. At most, maybe updates on Tiana and perhaps the Epcot night show, probably nothing more substantial than that. That's just my own speculation, I don't know either way.
