Oh yeah, you shouldn’t. But people do this for fingerprinting, bot detection, and other “adversarial” scenarios where you really don’t like the person executing your code. It’s somewhat plausible Google would use this technique to do something scummy like this (although that is not the case).
Swapping CPU manufacturers entirely? I’d just start my kernel config fresh. Pull up the old one next to a new (default ) one and go down line by line. Odds are there are at most a few flags that would need to be changed, but it’s a good chance to reevaluate your previous decisions too.
It makes a HUGE difference in compile time. Which only matters if you’re building your own kernel anyway. It’s a solution for its own problem.
I think it’s a good learning experience though. There is genuinely a lot of stuff in there that you can easily, safely remove, and reading up on all the less obvious flags is fun.