I have found that I have 2 cans of drink in my inventory, that were in my backpack before the update, and when I drink from them the can is not removed from my inventory and I can drink from again.
I tested it and saw that when drinking from the same can a number of time I went from no hydradion icon to a dark green hydration icon.
I found that if I find new cans of drink and put them in my backback and drink them they are removed, as normal, after the drink has been comsumed.
I have not tested to see if the drinks are still in my inventory after I have logged out and back in again but will update this post when I know.
After logging out and in the drinks are still in my inventory and I was able to use them multiple times and they remain in my inventory.