For a few years, especially with the stock market? Is that all you think they would do throughout that whole time?
They do way more than just minor stuff like that, such as nostalgia and much more deeper stuff for the general audience. Unfortunately, this game’s post-launch development has done way more than just those minor stuff you mentioned, has taken up so many potentially opportunities to keep brining in the general audience with some originality in that basic sense. These you mentioned DLCs would be too generic compared with what has been brought up here. While an Ice Age style DLC may be an exception, due to many potential original opportunities for the audience, they would want to do way more like all first three games have and what will become of Planet Zoo. But, what else could they do to do that in this short about of time, especially since they aim for general audiences and not specific party groups like “for hardcore fans” or “for the community of this or that”.
It has to be a strategy to draw in general players with more than just only animals or just only buildings and so fourth, they find ways to attract a wide audience, like Return to Jurassic Park for that nostalgic feel, the Raptor Squad Skin Collection because it represents audience attached visuals of their favorite characters, and so fourth.
Doing the same thing with big DLCs and free updates like what were done here (core wise), except your Ice Age suggestion, would be too similar and generic when compared with this game’s big DLCs, even with some basic differences within them. Essentially, not too many identity differences to keep both games unique in the right way, and one would expect more than just a typical Ice Age DLC or typical packs for less audience/community engaging stuff as oppose to the balanced number of engaging elements this game uses from the film series from a company type like Frontier Developments are in.
This game was well placed within the active trend of the JP franchise, which was expected to run at an estimate of three years after launch and, in another perspective, that three year trend is estimated to be as long as the series as a whole, a good opportunity to make marketing advantages for not only the companies, but for the game itself, something a hypothetical sequel or any big game for the franchise from Frontier’s part, like what they did with Jurassic World Evolution itself, would not be able to do healthily.
If this 2021 game is a Sony Pictures IP, like I believe it is, there are at least three options I can think of that would be well applicable for this business concept of theirs.
A lot of the features that were wanted in the current game are ones the engine isn't really set up for. The Mosasaurus and fliers are not something easy to do other than the container building type which is a lot less customizable than a full enclosure.
For the Raptor Squad, that seems to have been doing well enough that Frontier was allowed to use them. If you remember, at launch there was a lot of things about not being allowed to use the dinosaur characters in it, playing it as making our own Blue and Rexy rather than just the ones from the movies. There was enough desire to let them be put into it, but at the same time they have nothing in the story to tie them in, which is something that could be fixed in a sequel game.
There can also be other mechanics tied into things to expand on it which are not currently supported. Actual breeding for instance could be a thing in a sequel with more of the aging and injuries and other things that were intended for JW:E (That was discussed in pre-release as a planned feature) that got cut because they couldn't make them work in time.
Hell, adding in first person, guest mode and other things could be interesting. A working Site-B could be done, and one of the things that I've wanted for one would be a Site-B island where dinosaurs could breed and randomly get different skins and some genes would only come from breeding done in the wild, you could then sample and clone with those and even continue breeding them for better versions of the genes...add a release to Site-B and a franchise mode that might let you transfer dinosaurs between parks would be interesting.
Adding in more options for things could be interesting, such as being able to ship some dinosaurs around for early anchor positions on a new island, or when a dino gets old and could die, do you try to keep it in with the higher rating, or sacrifice it to a younger one in a duel to up the rating of the new, planned star.
Additionally, a lot of the awkward issues such as the way Bathrooms were implemented would fit better with a ground up rather than dealing with the current way things are.
The real hat trick would be to have a good chunk of the current dinosaurs not directly in the game, but if you have JW:E and its expansions, they count as DLC for the new one. It rewards current players and keeps the games viable for new players to want them in order to expand their options.
Hell, a lot of the vehicle skins could work the same way for unlocks...and if the sequel had new building designs, well, if you have JW:E, why not have the older style available for it.
But that's without major engine upgrades potential between the games...
