I’ve had my AirPods Pro for two years now and I’ve had to have both (left and right) replaced twice because of this. Unfortunately they are now out of warranty. I hope 2nd gen doesn’t suffer from something like this.
Got them replaced both for free in an Apple store, I thought only one was bugging out but their test machine said both were "broke". It was out of warranty since well over a year.
I have done this succesfully as well, even in another country than which I bought them in initialy. Nearly 2 years out of warranty at the time of replacement, replacement itself was not a problem.
This is in line with my experience, I got both AirPods Pro replaced out of warranty a couple weeks ago, even if only one of them was presenting issues. Apparently, the machine they use to check said both were affected.
I got them replaced in Spain while the original purchase took place in Germany.
i bet the rolling out of this program so close to the 2nd gen release is a subtle acknowledgment from apple that this issue is endemic to the 1st gen, and it's fixed now.