So, a friend of mine recently returned to the game and tried LFR. I was under the impression that if you queue and get a wing in progress, and complete it so that you're saved to the last boss of that wing, next requeue should guarantee a fresh raid. All posts I'm finding about it are years old and confirm my old presumption.
However, he seems to be constantly put into the LFR wing where Anduin is defeated and the raid is on Lords of Dread or Rygelon several times in a row even though he's already locked to those bosses. He's sick of wasting time rekilling bosses for no loot or eating 30 min deserter for nothing (he tried both approaches). It mostly happens with this wing, esp. since all 3 bosses drop tier pieces so it sucks much more to lose 1st boss of the wing in comparison to the other wings.
Did Blizzard remove the guarantee "fresh wing if you requeue"? I can't find any info about it.