If that happens half the player base will unsub. He seems to be Yoshida's precious bby too, though, so I'm not too worried about that. We need his newfound genuine idealism far more than some people want to admit.
If some people's prediction about Thancred changing sides (or thinking about it, however briefly) end up being true, it'll probably be him getting the punch.
Though if he actually does, in my mind atleast it would be to find out the other side's thoughts/spying then outright joining them.
I don't think we're going to punch Alphinaud. Despite what some people may think, idealism is not just for kids, and being cynical all the time is not "grown up." We actually need Alphinaud's idealism now more than ever, else we'd be liable to drown in despair.
Thancred, of all people, is probably not going to turn tail. He was possessed by Lahabrea for the latter half of 2.0, so he knows the cruelty of the Ascians firsthand. Probably just tailing the Warrior of Darkness, though why Darklander didn't just teleport or whatever remains a question.
I'm generally forgiving toward the Deftarm, since he is kind of new to the whole "individuality" thing on top of learning to be an adventurer. He's also literally struggling to remain himself, so...
Seeing how the beast quest stories usually progress, I am betting the Deftarm will briefly fall back to the Onemind and we'll yank him out of it by either force or words of encouragement.
So much this! Since Heavensward launched, and all the MSQ up to now, It's really setting the stage for our WoL to just say: "Screw it all, I'm leaving! Deal with your own crap for awhile!" Which would be perfect for the next expansion being 'at sea.' Our WoLs get on a boat and just sails away. We are adventurers first and foremost after all. Probably find some new land, become some hero there and by the time we are done fixing their problems, we head back to Eorzea, to find it in shambles.
As much as people want this, it won't happen. Even if the WOL did leave, they'll just be doing odd jobs for other people in a new land, so no different from what they do now outside of world saving. Eorzea isn't going to get ruined again anytime soon since there won't be any major world changing events for the sake of keeping things consistent for everyone no matter where they are in the story.
There can be a changing of our affiliations though, we could still operate in Eorzea even while not being a part of the Scions. and GC are loose enough with adventurer participation anyway. besides, we are going to be leaving eorzea at some point with expansions.