Given that virtually everyone would have taken their MBP to an Apple Store (even those who decided to not get the repairs), Apple has a list of most people who experienced this issue.
If they want to maintain their reputation for quality, it would be wise to find a way to reimburse people who they can confirm (with said previous apple store appointments for this issue). They don't need to reimburse everyone, but they could definitely find a way to rebuild some trust here.