It seems BA are planning to shift their route to Funchal back to LGW in W24. There are no flights from LHR on sale (unlike very other route) and BAEF have not released their flights for W24 yet - which indicates it will form part of their network.
After all BA’s over dramatic stance during the pandemic, LGW has basically returned to pre-pandemic in regard to destinations served. Apart from Jersey and Tirana, all the LGW routes have moved back from LHR.