Switching true stealth for actual stealth won't change anything. Only a handful of champions in the entire game have a reveal meaning that it will only EVER come up in fringe cases. In most games (against basically any mage in the game) it functions the exact same. The only difference that would come up OFTEN enough is LeBlanc E.
The only other champions that would benefit from it switching over would be: Caitlyn, Fizz (on R), Karma (on W), Kled (on E and Q), Lee Sin (Q), Lulu (E), Nidalee (Passive), Rengar (ulti only on closest target but doesn't matter since that is how it works NOW and since his ult fades when he jumps he loses the sight), Poppy (R), Thresh (Q), Twisted Fate (R), and finally Zyra (W).
Almost all of these champions are going to be bad picks into akali regardless (TF), is way too situational (Nidalee, Zyra, TF, Rengar, etc.), or are simply not going to be interacting with her for 90% of the game anyway which is......almost the entire list since there are barely any mid laners here and most people's problem with the shroud is in laning phase.
What I am getting at is changing the ult from "true stealth" to "normal stealth" is going to do absolutely nothing for the champion in like 90%+ of match ups. You are still SOL playing someone like Xerath or Lux into her since you are going to be JUST AS BLIND as you would be if it was still true stealth.