Okay, now that I've looked at the actual leak, maybe it is slightly more credible than I thought. The source being a Technical Artist means they're fairly low in the ranks based on the job description, with the majority of knowledge being for JWE, they have at least crafted it semi-realistically (though even if was a real conversation, I'm not sure how far down the trolling goes in Frontier).
It also was made pretty recently (15th of April), the day before the Carnivore DLC was revealed, if they were talking with someone working on it, then there wouldn't be much harm in disclosing it.
Going further beyond that seems dangerous for their job, though the actual claims made aren't the most outlandish, making decorative rocks a more likely interpretation than terrain tools.
Knowing two dinosaurs and knowing there is another, but not knowing what it is, seems to be bait for speculation, which is a little suspicious.
Also growing plants specifically for the feeder seems like a fairly mute feature, it fits with the natural theme I suppose, but it basically just saves a bit of money at a cost of the space most people don't have (which come think of it is a very Frontier move). It would have to be a bit cooler to make up for it.
The December classic stuff seems to be in it's infancy, which sounds about right for the time frame, though calling it 1993 seems a little odd (albeit not out of the question), considering Sorna was mentioned.
Knowledge of a five year plan seems a bit far fetched and I think most of the "New Projects" section was already known/speculated to be that way, so a bit shakey.