We've had deck building restrictions (Limit 1, MWL), and uniqueness. While the latter is technically a functional change, it doesn't change the written effect on the card. All the current changes are pretty easy to remember.
That said, I hate the uniqueness changes. Those cards should have just been banned too.
If you start tinkering with the costs, abilities, and written effects of cards you massively increasing the complexity of an already hugely complex game, and you're demanding players remember changes in gameplay.
I don't know about you, but I forget triggers now. I'd certainly forget a dozen cards not doing what they say they do.
Final point... I don't care if other languages have had functional errata. The English version, which is the native version of the game, largely have not. I do not wish to start now.
Bans. We need bans.