Since New Vegas, Bethesda said they're unlikely to let any outside studio release a title in that franchise again.
IMO, the nothingburger Fallout 4 update Bethesda forced out over Steam—which was not the big update one with superfluous Enclave garbage, but the earlier one almost immediately after FOLON's release—was deliberate in order to break Fallout London. (Giving it more negative reputation?) It was a stupid update which fixed basically nothing, and added nothing of substance.
Every update to the main game breaks the script extender used by virtually every quality mod. Which is why the most stable, least faff way to get it going is the final fixed version release on GOG.
I know it sounds like foil hat conspiracy theory, but the coincidence is too strong.