The ZG boost by mages has been a bannable offense since the 2019 classic where as soon as ZG opened trade and lfg channels were totally overflown by mages offering ZG boosts for money.
Ppl got endlessly annoyed by it that so blizzard made it a topic in the report window, limited the number of mobs affected by consecration and blizzard (yes palas were doing the same).
So now as soon as you are offering boosts, a number of players will report you.
That npc ur talking about does it happen to be named “Undying Laborer” ?
I made a thread about that here: Undying Laborer kited into Stormwind