Fisher has made considerable change to his training and coaching structure. It wouldn’t surprise that he also makes change to his racing structure.
This year is an Olympic year, his focus is on that. As is anyone who has a legitimate shot at medaling.
After which time, given he doesn’t have his old coach, road championships in the US and even cross country (which he has said many times he enjoys) might intrigue him.
Realistically he could right now break road records up to and including the half marathon. The marathon is a different matter and would require different preparation. I wouldn’t count his ability out to run a sub 2:04 marathon but he may just say nah to that distance, hold every US record from 3k up to the half, have some Olympic and World medals and move on to the business world.