Mike Hearn lol, I thought we stopped hearing about him after his rage quit during the block size wars in 2016-2017. Hes not relevant in our industry any more, nobody cares what he says or does.
Mike Hearn is one of the early Bitcoin developers, right? People won't forget the contributions he made to the project while he was working on it. Same goes for Gavin Andresen. I bet Mike Hearn will join Bitcoin-based forks that are focused on bigger block sizes. I'm talking about Bitcoin Cash and Bitcoin SV. I doubt such projects will gain the spotlight with Mike Hearn on-board. But you never know. Especially when crypto land behaves in many strange and bizarre ways.
Whatever happens in the long run, you can rest assured Bitcoin won't be going anywhere. It's "too big to fail". Wishing the best of luck to Mr. Hearn in all of his future endeavors.