Of course, it’s possible that Buck will be absolutely fine when Abby rolls back into town, but Connie Britton isn’t returning as a series regular.
If Buck entertains any hopes of restarting their relationship but doesn’t want to leave the LAFD after fighting so hard to get back, then something is going to have to give.
While hanging out with Christopher can’t provide Buck any closure with Abby, hopefully he’ll have some good times to go with any angst that comes with Abby’s return.