No, because only the dev knows what will happen in the future. That's what multiple saves are for, do another solo Ashley playthrough & you're covered either way. The TAB key is your friend.
It's not mislabeled, harem doesn't mean bang everyone in one playthrough.
The dev has explicitly said there are harem route(s):
There are literally harem variables in game now:
We also don't know if missing some points & scenes will actually lock out polyamory in future. Depends how tight the requirements are going forward.
People complaining about the presence of harem content in this game are equally misguided, at this point they're completely optional & you can solo girls to your hearts content. Choice is a fine thing.