Well if you played before the dungeon was removed then updated you lose the spanking scenes with Jessica and Gwen.
I assume a few will be restricted based on choices. Probably any follow up scene won't be available if you didn't show interest in a girl. This might be problematic on some grey choices were the player was playing as a Hero and didn't want to take the Villain route of fuck first regardless of context. Most of those have been shelved for a later yet to be determined date though...
Pregnancy being optional it's hard to say if refusing will lock you out of any after sex scenes that play up that kink along with different dialogue like the girls obviously wanted to be knocked up. However given how Kana reacts ArcGames isn't that kind to those that want to pull out
She is so disappointed if you do that. The follow up children scenes would also be locked out but that is more general content.
There was teased early on that we could kill people. If he ever offers that for a girl then of course her content would be locked out. A few of the antagonist characters come to mind but that was long ago and plans change.
So far it's mostly wild cards as ArcGames hasn't written any real consequences yet. The girls this would currently apply to have been on the back burner for awhile now...