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.
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.
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.
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.
Apple’s position would then be: great battery life unless you need to run old intel software.