Is not reasonable to expect the full roster in a sequel... and to be honest i would be perfectly fine with some animals being resold in DLCs later on if that means improved versiones. A big chunk of base game and early DLC animals actually: okapi, snow leopard, siberian tiger, african wild dog, orangutan, cheetah, red panda, giant panda, spotted hyena, nile monitor, saltwater crocodile, gharial, bactrian camel, black wildebeest, aardvark etc. Then there are some that i expect with an improved version in base game: lion, jaguar, bears, wolf, zebras, giraffes, elephants, greater flamingo, ostrich, american bison, koala, kangaroo, reindeer etc. And then there are the ones that i would cut and not miss at all: himalayan brown bear, aldabra giant tortoise (don't hate them, could be dlc material later on, but idc if they are not there or back again), arctic wolf (just add a variant to regular wolf), bonobo (can live without, i don't actively want them gone but if they are not ther... oh well fine by me, chimpanzee is good enough for me), bornean elephant, dall's sheep.
And then there is the cathegory of: they look good but i don't care much about them personally so add them to base game so i don't have to pay for them again: coyote, red fox, skunk, cuvier's dwarf caiman, dama gazelle, nile lechwe, tanuki, big horned sheep, wisent, saiga, wild boar, american flamingo and the whole of the barnyard animal pack (and then i hope for them to be very selective with which domestics they add later on).