Wells won’t be fired after this year unless they have a disastrous season which I don’t think is going to happen. They will likely win 8+ games this year.
If they ever do need to replace Wells, assuming Gary isn’t a HC somewhere else, I would bet they would at least reach out to him.
I don’t think Gary would take the job if offered though. He’s been there done that and knows just how tough it is to build a winner in Logan. I don’t think he wants to go through that again.