[Kushan]

...you've lost me. The equipment being removed from the exchange will deal specifically with FTTC links. The backhaul link Virgin provides to Sky will have nothing to do with said FTTC equipment. That'll be Sky's equipment, which BT won't touch. Anything after that is Sky's responsibility (i.e. Virgin) and BT won't go near it.

It's not like there's a big box labelled Sky and a big box labelled Virgin with a cable going between them and BT will just be like "Well say goodbye, Virgin!".