Nothing new. You can do this in pretty much any run to varying degrees of effectiveness, with ones that have transitions being easier. I remember getting a group in Neverreap where the tank decided we were ignoring the Dhamels near the end. We jumped the gap to fight the final boss after clearing the gate keeping adds, and the Dhamels were left standing there staring at us. After we killed the final boss, as a MCH I decided that I didn't like not killing them and decided to shoot them from across the gap. Ended up being a bit of a Crowning Moment of Heartwarming when all three of the other party members decided to come back and join me in killing them with what ranged attacks they had.....
Realistically, you can do this to any boss in the game if the tank can survive the adds well enough. Just pull everything and rush to the boss, before holding the adds at the gate until the 15s pops up and locks them out. I'd advise against it though unless you're premade. I got a tank in Wanderer's Palace earlier who decided to speed run it at the valve stage, and pulled a large chunk of the dungeon into the second boss fight, which resulted in our healer being killed and us having to use melee LB to kill what is arguably one of the weaker bosses in the game in order to keep from wiping. Cue the votekick immediately after.....