I'm contradicting myself in the two posts I just noticed ^^. What we had happening:
Every time the first hatchling died, we hit p2. Unless tank dps was incredibly consistent in the 4 pulls we needed, I suspect it is a trigger. The number of druids would then be a second trigger that works as a soft enrage.
It's hard to tell as both tanks were very equal on hatchling dps, but it seemed to happen all 4 or 5 pulls we needed to kill the boss.
However, the advise for the OP stays the same If the fight lasts too long, see if the tanks can improve on dps. Having the hatchlings up in p2 is always a dps loss as you end up killing those instead of using the burn phase for Alysrazor and if you're able to kill the hatchlings before the X druid trigger, you're winning time there.