Apple are more likely to choose "fat binaries" again. They're possibly the only company who could announce an architecture switch, OS revision bump, and corresponding changes to development tools all at once.
Also, they're known for having pulled this off successfully, twice (68000 to PPC, PPC to Intel), which certainly would lend them credibility if they decided to go for it.
I would buy such a laptop with zero qualms about them bungling the migration. If it had a decent keyboard and got rid of the touch bar. I'm much more concerned about having my experience ruined by those.
Aside from missing the escape key when I'm in VIM, the Touch Bar hasn't "ruined" my experience with a Macbook Pro.
I'll readily admit the thing is more cool than genuinely useful. It's just not such a gimmick as to actually "ruin" an experience. And the gain from TouchID offsets my pain from not having a physical escape key.
In this respect, the Macbook Air gets things right.
WRT the keyboard... your mileage will vary. I hated it at first. Pretty used to it now.
I don't hate the keyboard. I tried it in a store and after getting over the surprise of the extremely short key travel distance, it is quite usable - but the failure rate, the annoyances, the potential out-of-warranty cost turn it into a complete dealbreaker. It is simply not reliable enough, despite the redesign. Maybe now at the second redesign it's finally OK but no way I'm paying for one until we're certain, and that certainty will take a couple years of real world usage to materialize.
Regarding the touch bar: Indeed the Escape key is what breaks the deal. Honestly if it began after ESC I'd tolerate it - expensive, close to useless, but tolerable.
Ironically you chose one of the examples that's already been over a porting barrier from a RISC architecture: Photoshop up to (I think) CS4 ran on PowerPC.
I would buy such a laptop with zero qualms about them bungling the migration. If it had a decent keyboard and got rid of the touch bar. I'm much more concerned about having my experience ruined by those.