I’ve noticed this Brewfest season that on the Coren Direbrew fight when Ursula spawns she can instantly barrel someone, rendering them stunned for 7 seconds or so. My understanding is that she barrels the person who hold top threat on her, which would ideally be handled by the tank or healer not dpsing her to avoid building threat while dps burn her down. But when she spawns and insta-barrels someone there is no chance to use this or any other strategy.
I would suggest adding a short delay after she spawns before she barrels someone, so the threat generation mechanic can be meaningful.