Still, the number of dinos alone would not freeze the servers, without what i like to call a "Breeding Explosion".
At a rate of 4x this is very unlikely to happen though. It would take some coincidence of a large amount of dinos being left on breeding at ideal temperatures or air conditioning/incubators, to result in all eggs hatching, and even then, offspring would not survive long enough to start breeding themselves.
Those "Breeding Explosions" used to happen on boosted servers when events with breeding multipliers still affected unofficials resulting in absurd 40x or more...
I would dare to theorize, that WC has just been cramping way too many maps/servers on each (virtual) machine, strangulating CPU/RAM ending up compromising the stability of the physical server itself.