I suspect you have offered some unnecessary information to the BT representative and had a somewhat misleading answer ( or you have misunderstood )
You don’t need the ‘status’ of the address you are moving into ( assuming it’s a standard dwelling, a house , flat etc. and not some type of a managed retirement home ) , you simply order whatever services you want , phone , broadband or both , the type of broadband available will be dictated by what that area has available , fibre to the cabinet, fibre to the premises or ADSL .
If the address is shown as already having a working line , it takes longer to arrange as the the provider of that line needs to send a letter/ email to the occupant saying someone wants to take over the line , if the address is empty , that letter goes unanswered, so after a while , because no one objected , your service is provided , if there is no working service recorded, this letter isn’t needed so BT service can be provided quicker
…you can order on line ( so you don’t speak to anyone ) , just put in the address and what type of service you want ) or speak to BT to order , but you don’t say a BT line exists , just that you are moving into the address and want service.
