I'm guessing 1-2 fps drops here and there wasn't enough for them to put their foot down, and I'm not sure that was a bad decision. I've played the game for hours and it holds up just fine on the Pro.
You can't be reasonable in these discussions. This is about nitpicking to the extreme.
It's obvious that delivering 1800p checkerboard is such a huge improvement that far outweighs some extra occasional small drops that no one will notice about anyway.
And it's unrealistic to expect that developers will spend time and money to rework the code to fix such minor things.
What they can do is to add more options like a full OG PS4 mode or much better a 1080p performance mode in every game.
In that case to each one its own.
This is what we should ask, that those with a 1080p TV should get a performance mode in every case.
But right now a lot of these patches are just rushed to have support ready for launch.
Basically Ubisoft is just running the game at an internal higher res and that's it. Close to zero effort.