Well, to start with BA charging for seat selection for non-status pax in CW is hardly a new thing and hardly a scam.
Looks like the usual 772 has seen a swap to a 77W tomorrow leading to the change of seats. Have you considered calling BA to have the seats reassigned?
In any case, they can get a refund of the selection fee after the flight if BA do not honour the original reservation.
Looking at EF, there are plenty of opportunities for them to sit together, with the best bet likely being 15AB.
