There is an equal balance of this being fake or real, though you must understand this: anyone can make anything seem so similar, just like with a game my little brothers have that I will only abbreviate here (SSBU). However...
I am a YouTuber myself with a different channel name. I currently don't upload anything now, but I am a subscriber to the official Jurassic World Evolution channel with the notification bell activated for me.
Reason I'm saying that is because when you turn on the notification bell for a channel you've subscribed to, you will get always notifications on your handheld devices (my Iphone in my case), your email inbox, and your YouTube notifications that the subscribed channel you've set the notification alert on has uploaded a new video.
And... if there were anything they actually uploaded, regardless if it was removed or whatever shortly, I would have been notified of it by now. In my experience with the official Jurassic World channel, there have been videos in the most recent past where they uploaded something, only to have been removed or whatever (i don't care) very shortly after their notifications and right after uploads.
If JWE posted an "Omnivore Dinosaur Pack DLC video", I would have been notified of it by now, leading to suspect that maybe this was fake after all. Although, based on a "leak" that was posted by a confirmed Nintendo staff member individual who posted images of a "full roster" for SSBU with fake (but cleverly well placed) playable character faces (with one or two of them becoming real in later months). On the contrary, a typical hobbyist on YouTube who made an "extremely believable" looking "leak" of a playable character for that respective Nintendo game.
Point is, this 3+ dino pack DLC could very well be either fake or real at best based on the research I posted above, with origins from being potentially from "anyone" on Earth, regardless who they are as anyone can make anything seem very believable. The only way to truly find out if this 3+ "Ominvore Dinosaur Pack" DLC is a thing is to wait and see...
(In my book, it's better to be safe than sorry.)