It seems the government, through the Competition & Markets Authority, is going to get involved
https://www.bbc.co.uk/news/business-52483453
That's more than aviation - major hotel events for example. But one would have really expected the Dept for Transport to have been forthright on what the legal position is with airline/air holiday refunds. After all, they licence them, and with so many transport operations running minimally, they don't seem to have a lot else to do.