That would completely ruin the gaming experience. They took part of that with Rag and SE, and most people will play on Rag, since they can basically get most of the creatures on Rag. They need to keep maps relative. I would probably stop playing Ark, if they ever put every creature on the same map.. It would also be a slap in the face for people such as myself, that supported the DLC and purchased the other maps. It bad enough they added Abberant creatures to the map as it is, which makes Abberation mostly useless now.