Just playing the odds here, I think he'll be back in the starting lineup at some point this season. Whether it's due to Rona, injury, underperforming, or the team simply falling out of contention there's just so many ways it could happen.
If Tua lights it up (like we all hope he does) or we have a shortened season then he'll play the rest of the way.
I do think Fitz has one final chapter in his story before he hangs up the cleats - hoping for a happy ending because the dude definitely deserves it.