I guess it really depends how much you want to play the game.
I am replaying the game on my old PS4 after handing over my PS5 so I could get a perspective of how it is for a new player with all the updates and dlc available to me.
From what I have tested, it holds up well. The Campaigns, Chaos Theory scenarios, and Challenge modes offer a lot when it comes to park management, the updates the game has gotten since launch have refined and enhanced the park experience. With Sandbox and Custom Challenge mode being the end goal in the game, where you could replay as much as you want with your own parks and dinosaur roster that could reach 122 different species if you plan to get the DLC.
The unfortunate thing is the longer you play the game, the more apparent some odd design choices and bugs would become. This does not hinder the overall gameplay experience but it would be noticeable if you played the game for hundreds of hours and know that support is pretty much over.
With that said, if you are possibly getting an Xbox Series S, would you be getting game pass as well? Jurassic World Evolution 2 is in game pass and you could try it out there. It has no DLC content with that option, but the base game is very beefy in what it offers. You basically have a healthy roster of Jurassic Park and Jurassic World dinosaurs and skins, and with the additional attractions, expanded decorations, and the many maps and variations the base game has thanks to the updates, that is more than enough to enjoy this game.
Once DLCs are on sale and you are interested in playing the game further, I recommend the Dominion Biosyn expansion and Malta expansion DLCs. They are the best as they offer more building sets, unique and well detailed movie animals, new campaign and chaos theory game modes, as well as new maps to play in Sandbox and Custom Challenge mode. Any other dlc would simply be adding dinosaurs that you may like, and I only could recommend them if you plan to play the game a LOT in the custom challenge mode and sandbox mode with a wider variety of dinosaurs, the more free form and repayable modes of the game.
Otherwise, I think at this stage there is no harm trying the game out. JWE3 could very well be launching alongside or around the time the next movie were to launch in summer 2025 which is a year away. If you were to nab the game as part of game pass and get the DLC after a huge sale, it would be fun if you like a good current get prehistoric park sim, even if the next title is a year away since the sales discounts these days are super steep and you won't get as much of a buyer's remorse. If this discussion is happening in 2025, I would say it would be best to wait so you could experience the sequel with a completely fresh first impression.
Feel free to ask any further questions!