Not only that. Also someone suddenly mentions MC's mom had passed. That obviously is totally out of sync with the patched intro, where the parents decided to rekindle their relationship and leave their kids to live together.
It would make absolute sense that Alice and the aunt don't really know each other. But of course they'd still know of each other's existence and would call each other aunt and niece.
Not knowing where dev will take the official story may make maintaining the incest patch pretty hard and/or annoying.