One point I haven’t seen raised is that if tariffs remain, they may favor very large companies like Disney a bit. Relative to their smaller competitors, it’s much more likely that a ginormous corporation will have the resources and influence to find a way around tariffs. That may not give them an edge in an absolute sense, but it would give them a relative edge that they might want to utilize. (Not saying that’s fair, btw, just talking about it from a parks perspective.)
I dunno. There is always a potential reason not to build. When numbers are down, it’s too save money. When numbers are up, there’s the rationale of “Why offer more at a time when we don’t need to do anything to attract more people.” On the whole, however, my understanding is that Disney has generally spent the most when revenue was either neutral or down (feel free to correct me, I know some people here know a ton about WDW history while I have a passing familiarity). I’m still relatively optimistic that most of these projects will go.