Does does anybody feel like mods could ruin the game completely in the future because it seems that with Dinosaurs being added thanks to mods not only would console players feel left out but also this could actually ruin new dinosaurs from actually coming into Jurassic world evolution in the future such as the therizinosaurus, what happens if therizinosaurus is added to the game in a Major DLC and nobody wants to buy it because they think "I got it so what do I need this DLC for in my mods collection on my PC".... You see what I'm getting at why would you want to pay money for something that you got in mod on P.C for free.
I can't speak for everyone, but I highly doubt that the inclusion of mods will limit my interest in getting additional DLC's. First, I doubt most people will use mods in their games. Yes, people will consider it. I for one, am very tempted by more accurate models, but understand that's a niche. Some people won't care to take the risk with mods. Others may be purists who believe in keeping their game pure and developer intended (this is how I am with Minecraft. I'm one of the few it feels like). Still others won't even know they exist. So, mods will likely not make a big difference to those players, and they will still be interested in DLC's.
Another thing to consider with mods is quality. Some mods are exceptional, but for the most part, mods tend to be lower quality then something created by a professional team. The janky animations, the existing dinosaur replacement, lack of sound files/introduction files, or lack of other quality of life features will simply make them less appealing than a well crafted dino pack. Therefore, people will continue to purchase DLC's when those DLC's have more features without the drawbacks of mods.
Lastly, I think it's important to consider the timing of mods. The game has been out for 1.5 years now. The player base is likely a huge fraction of what it was, and the return Frontier is expecting for future DLC's is likely diminishing. We don't know for sure, but it's possible that Frontier doesn't have an interest in providing additional DLC's. They could be getting ready to cut and shift to other projects. Modding in these cases, is actually a way for people to show their appreciation to Frontier by creating fan based content. It's actually a good thing.
I know that not everyone can appreciate mods. Even those who have a PC may not want mods (I will likely be one of those). I think it's still a valid statement to say that the unmodded game is just as fun as the modded game. As of this current moment, the mods really don't add much additional content to the game, and I am very happy to continue playing JWE without them. Mods don't really change my mind about this game, or about future DLC's