I’m just not understanding your thinking, are you expecting devs to implement changes that are only helpful and not expect any cons?
Well, that was always the norm in bb, so yes. There were many good changes in bb that didn't have any cons, or the cons were only short-term.
Gdp-implementation:
It's what saved bb back in the days when everyone was playing LI & m2m. It had some short-term cons, as managers had to adapt their teams a bit, but no mid-term, or long-term cons.
GS goes down upon buying a player:
Again, miniscule short-term cons, and no mid/long term cons.
% of sale price fee reduction:
Some short-term cons, and no mid/long term cons.
That's how it always should be. Short-term cons are to be expected with any change, but there shouldn't be any mid/long-term cons. If there are, than whatever change caused it, wasn't implemented properly.