Copy and pasted from the main patch thread:

 

Something that's not exactly a bug but is kind of related is that for a character using Frenzy their endurance is still colour coded (so the first ? of ?/? - representing the endurance cover up - will represent your endurance in the normal way, light green being 100-75%, yellow being 74-50%, etc.). What this means is that while you don't know exactly what your endurance is, it does mean that you can tell to the nearest quarter making heals easy to time for effectiveness, and in essence more or less defeating the purpose of covering up endurance in the first place.

 

I'm not sure if this is worth it or even desirable to patch in, but it seems to run contrary to the idea of frenzy giving you no knowledge of what current state the character is in. I suppose to a more meticulous extent you could just keep track of the numbers in the combat log to work out health, but as this is extremely tedious I can't imagine people would actually bother.

You get the damage numbers too, so if you want to you can track your endurance quite reliable. So... while you shouldn't know anything, you CAN always know everything about your endurance - metagaming ftw.