1. AI replaces a non-trivial fraction of human employees.

I mean, it's pretty clear that's going to happen. How could it not?

The only question is whether resources are optimally allocated at the moment to prepare for this. That seems unlikely at best. So yes, there is probably a bubble, and if so, then yes, it will pop, and then life will go on, with resources better allocated. Just like when the dot-com bubble popped.