Kein, I think you're worrying a bit much. There is no need for Larian to bother changing any conception/product art, or re-writing the Zandalor's diary journal entry.
I'm not sure if there will be much "flirting" dialogue between the party members before the ending is determined, and if there is places for that, it'll probably do a check for their personality profile compatibility anyway.
If the worst case scenario comes about(your scenario) and everything remains as it is I hope there won't be a forced romance. I just find it obnoxious and predictable.
What do you think the co-operative dialogue system is for? It builds a personality profile of the characters and their values, and that will determine their relationship at the end.
