I'm really not understanding why people think this is a good defence - putting these features into a game that, as you yourself say, is supposed to promote conservation and positive animal management in turn promotes the bad practice of marine animal training and the circus acts associated with that.
Personally I hope that if we get a marine animal DLC, it's just for zoo staples, such as sea lions and other pinnipeds, penguins, and perhaps sea otters.
The game is meant to promote conservation, yes, but the whole reason the practice has been on the decline is that it is cruel to animals in captivity and an animal in Planet Zoo is just a series of zeroes and ones. All it takes to make an animal happy with a 4 sq meter enclosure is to modify a couple zeroes and ones.
There are many video games that involve killing people or killing animals, neither practice actually hurts anything real. If we felt that having killing in videogames constituted cruelty to humans, there'd be a lot fewer games on the market. If it's a game, there's no harm done. Kicking a chicken in Skyrim isn't cruel to animals because no animal exists. Any gauge of an animals wellbeing is based on a formula and hard coded variables (that can be disabled in Sandbox mode mind you). In Jurassic World Evolution, another Frontier game, you can have dinosaur fights and have carnivores hunt herbivores down for guest entertainment or appeal points. The more fights your dinosaur wins, the higher the appeal. If it's okay to kill fictional virtual animals, okay to kill fictional virtual people, why are all these moral limitations now in place for nonfictional virtual animals?
The game may want to promote conservation and that's fine for the game to do (which is why I said I don't think they'll add it) but you have the ability to treat animals poorly in the game already. You can give an animal a 2x2 enclosure if you want. Their welfare will be low and guests won't like it, but it's an option (again, an option you can disable in Sandbox mode). You can have animal fights by having more than one male in a mixed gender group. Guests won't like it but again it's an option. These are all things you
can do. Just like in Planet Coaster you can make rides that have enough G-forces to kill people.
These decisions however, have consequences. In a similar way, in a hypothetical marine animal DLC, you could have the practice of marine animal shows cause some guests to feel happy and other guests to feel upset. You could implement a system similar to Planet Coaster where different guests are in categories, one of which could be conservationist. We already have an ingame system for advertisement, perhaps it's time to implement a media system or more targeted advertising?
The bottom line is that there are ways to implement this feature while still getting across a message of conservation. If someone who is ignorant of the issue of marine animal training plays Planet Zoo today, they learn nothing. Of however the feature is implemented as well as it's consequences, they can walk away with an understanding of "well, the shows might bring in some guests and a little extra cash but it really causes health problems with the animals, causes stress, and leads to a lot of problems, maybe this isn't such a good idea." It's just like with guest-walkthrough habitats. Have too many guests and the animals get very stressed out, the player has to consider whether causing the animals stress is worth extra guest happiness. I just don't think blindly ignoring the issue helps conservation efforts at all. If anything, it'll leave players wanting this feature more.
At the end of the day, I hope Frontier does create a DLC for marine life. For one I would love to relive Zoo Tycoon, I'd also love to have player choice to include marine animals in my zoos. Unless the developers are planning a game called Planet Aquarium.
