Stats and/or old enchants like defense rating on zg warrior head enchant not being not actually being counted (was causing out tank to get crushed for 10k+ on nightbane)
Pallys no longer generating threat
Nightbane crazy buggy and locking you out of the fight for 30min if you wipe during air phase
Mages and warlocks actually being able to aoe the skeletons during air phase
and tons of other bugs with specific classes/specs
Not sure what the beta test was for but some of these are close to game breaking
A warrior with shield block up should be uncrushable. You have 20% base avoidance, shield block gives 75%. A warrior only needs 8% more avoidance (approx) from gear/talents to be uncrushable.
Passive uncrushability, without shield block, is indeed not possible in phase1 but unless it is a very fast hitting boss like prince you should be able to avoid all crushing blows as a warrior by just pressing the shield block button.