Yes, pension funds do fund a lot of commercial development. It’s not as big a section of the sector as it used to be (overseas investors and wealth funds have encroached a lot), but it’s still significant.
Of course the reason why pension funds invest in commercial property in this country compared to others is that we have worse state pension provision and we do not have the large institutional residential ownership that other European countries have, with their more equitable tenancy laws.
I doubt that the office buildings will stay empty - they may cease to be offices, but there’s enough demand in the residential sector for them to be put to good use, provided planning legislation keeps up.