There's a part of me that hopes piano playing is like riding a bike, and I'll miraculously turn out to have somehow not forgotten how to play, but I somehow doubt it. If only I hadn't let my skills lapse over the last 30-odd years!
I have taught quite a few adult 'returners' as well as those starting from scratch and I would say that however rusty you are some of the old brain wiring will have persisted although it might take a while to re-surface!
As an adult returner, I can attest to this. But don't do what I did which was to get out pieces that I knew I used to be able to play, try and fail to play them, and get annoyed.