Yeah, forced TFs of pretty much any kind are out and the ones that are in the game are of the 'We'll warn you beforehand and give you a chance to avoid it' sort. Well, the seasonal encounter with Kas that can get you demonic eyes doesn't explicitly warn you, but by that point you're expected to know that getting nasty with the sex demoness is likely to have some consequences, and not just to how gaped your hole(s) are going to be afterwards.
The game could do a gender-bending transformation via NPC but since that's a huge change it would have to be one where you're warned beforehand and have some way of opting out, like Kas in the tutorial (where the consequence is obvious and you can say no) or the Witch's Corset which warns you before you pick it up that wearing it will do things to you.