Hmm, what makes you think all of that wouldnt be in the game with them?I don't agree with adding cetaceans to the game if only because they would be very boring. Big body of water, no decorations, no natural features. no enrichment items, no feeding stations and done.
If we now asume they do add them, then I am 100% sure they would get enrichment items and feeding stations. Enrichment items can already be placed in water and float, so they might even be able to use some of the balls already in game for cetaceans (aswell as making some new)
Aswell as you can already decorate and put plants underwater, if you are a talented builder I am sure you could already built Atlantis (I am not)
Its very likley if they would make them, they would also come with new decorations and special plants. (Seeweed and such^^ )
The main techincal problem I see myself is actually that a tank would need a special entrance. I have no idea if such a thing would be easy or very hard (impossible?) to make. Which I guess also depends alot on Frontiers plans when they started to make the game - if they indeed planed in fully marine animals (even if maybe not any mammals) from the start, its probaly no problem. If they didnt it might be harder. But yeah, again I cant really tell
But enrichment items, decorations and plants dont look like they would be a problem at all. (Ok, maybe they wouldnt have a need for any seeweed or other water plants at all, but decoration would still be possible) They could be of course, I just dont think they are.
The human intercation thing is a point that might be true, but personally I dont see it as a problem, as it also goes for many animals already in game. Elephants and Rhinos for example do interact with their keepers on a daily basis aswell. Depending on the zoo in direct or protected contact. Apes are also having lots of contact with their keepers in real zoos (though always through the cages in this case, unless for currently hand raised offspring, of course). Actually the more I think about it almost all animals in real zoos do have some kind of contact with their keepers that is more than feeding and cleaning, many also get kinda trained for transport and/or medical purposes. This is not always done in sight of the guests, but its there.
Considering its already missing in PZ (especially for Elephants) I wouldnt miss it for cetaceans either.
(On a side note, the keepers walking in predator habitats as its nothing are also not very realistic either)
Anyways, I will still remain hopeful, but I do know the chances to get them are probaly under 10% or so