TalkTalk putting LLU into the exchange is the reason they can now offer service to people who could already get FTTC from other suppliers - it has no bearing on the fact you can now get FTTC at all. Either BT have put in a new cabinet to serve you or someone has made a mistake in the database and the order could fail.
Still odd that it has accepted an order for FTTC though, sounds like a mistake. It sounds like a small exchange, so the fibre cabinets won’t be connected via that exchange anyway. They’ll go to a larger exchange.
I wonder if a new cabinet has gone into the exchange car park or something, where it’s not visible? Usually they’re on public land outside the exchange but once I saw a cabinet actually in the exchange car park itself, in North Wales.
OP, if you put your phone number into the BT Wholesale checker does it show a cabinet now or still no?