the only "nerf" i can see them do is make it so the water no longer gives healing done towards your healing done in WZs (because 2 medals really are a big deal).
I'm a stealther and i use the water (surprise) and it's amazing. The even better part is, you can mail it to your alts and use it on them! So that means NONSTEALTHERS CAN USE IT TOO!!!!
Stealth has a somewhat advantage because they can vanish and drink and and go back in, i'll give that to the complainers, but once they drop combat, you do too (unless you're facing more than 1 person then it just sucks to be you.