I have an Iron Golem farm that worked well in 1.15.2. I thought the only difference was that the working stations were no longer required in order for the golems to spawn. They still spawn, but inside blocks. They spawn inside both transparent and solid blocks, as shown by the screenshots.

This severely impacts the spawning rates, since they get half stuck inside the wall of the spawning platforms and are no longer pushed by the water stream. They just sit there and prevent any new golem from spawning. The amount of iron ingots (and poppies) that I now get from this farm were significantly reduced.

Personnaly, not a big deal though, I already have plenty of stacks of iron blocks from the previous version (1.15.2), but it could clearly affect the game experience of other players.