Mind Vision will be disabled in arenas in patch 2.4. There is currently a bug with it on the test realms. Casting Mind Vision on a player that’s drinking causes that player to stand up, and canceling their drinking.
Priests are currently able to prevent any player from drinking; Mind Vision does not require line of sight and the whole arena is within range of the spell.
Mind Vision will not currently work in Arenas with patch 2.4.0. We are working on a technical fix for this in the meantime.
I wonder how long this temporary change will be.
Mind Vision can interrupt drinking on the live realms as well. (Ab)Use the power while you can.