I think whatever situation there was with Cora/Henry/Leo/Eva back in the day is gonna “bleed through” into present day events. Even though that previous generation are all dead, something to do with all of that is gonna be dredged up in present day. Of course, not knowing for sure what those flashbacks will entail makes it tricky to predict what that something that bleeds through could be.
Assuming that Regina and Snow have progressively been getting along better in present day, (we have no evidence of that really, it’s just what I hope happens), something from the past being brought up again could be a setback for them and for the whole family, which means whatever it is would also affect Henry. So some sort of flashback drama involving parents and children could be fitting. That could also bring the “blood is thicker than water” theme into it as well.