I'd be surprised if you weren't getting FTTP considering the estate age is similar to everything around you. BIDB doesn't know anything special about the Openreach plans for deployment so don't read into it too much.
Whilst it's true that bidb doesn't know anything special, there's a distinct difference between planned and unplanned premises.
The source of data changed, that's likely why it changed from planned->unplanned, and it's likely that nothing itself changed about the premise and would have always returned "unplanned".