First, I would suggest establishing a clear line between work and social, the higher up you go, the less friends you have. It’s great that you tried to help them initially and now it looks like you’re getting fucked unfortunately. I would advise staying away from these people on a social level and continue to work together professionally, clear line of separation.
Since the company was lining to performance management them, then they must have not been performing. Unfortunately in the corporate world, people are happy to palm problems off to other departments. From what I’ve read, it has been 2 years since, and not knowing how long they have been in the company, making performance management and termination a tad more complicated.
You can’t get them fired for no reason, but you can report your conversation to HR and have this logged as inappropriate and troubling. In all reputable companies there’s a whistleblower system where you can anonymously report things on ethics, mismanagement, toxic behavior etc.
In sum, keep it professional and avoid social, if they are not performing, they’ll end up getting performance managed out soon enough.
It protects you from the collector.