I was wondering about this but I don't know the new content so wanted to avoid specifics like this and focus on general principles (maybe a bad thing, maybe a good thing, certainly an interesting conversation).
I don't find writing "zerg" in the LFM to be productive due to the unfortunate negative connotations. I usually just write the quest that I'm doing and whether it's an elite BB run or farming and "starting" or "IP". Sometimes I add "byoh". I go through quests as quickly as possible ("zerg") and through an entire life - where I never put "zerg" in the LFM and almost constantly pug - I might have 1 or 2 people get upset at my play style. I've done a dozen or so lives like this on multiple servers ...
"Fast" or "zerging" is the norm, at least in my experience, if it isn't your norm, that's okay, post "no zerg" in your LFM and I'll know to avoid it so that I don't ruin your fun.
You're responsible for your own fun, be responsible, put "no zerg".