On the one hand, it's been obviously economically a good idea to require this for about a decade, both because PV is cheap and would pay for itself even at full price and also because doing it construction time is cheaper than doing it later.

Even moreso now, because PV is now cheaper per square metre than tiles or fences, even if you don't hook it up to the grid afterwards.

On the other hand, this is the UK so maybe. They did Brexit and somehow Farage hasn't been deported for the consequences.