He did it in a pretty silly way. The post as a whole is poor(!!!) with the last paragraph nearly youtube comment level. It's fine that he dislikes Kojima but why not discuss his concerns in detail within the post instead of throwing around extra punctuation and three word sentences. It's not a big deal at all but some effort could be put into it given it's his job. Just wish writing in games journalism was better in general.
Well, he's discussed his dislike for Kojima's approach to Ground Zeroes, which I'm betting is a huge part of it, at length before. But people who are not fans of GB will probably not know of that backstory, so he probably could've explained it a bit better.
Still, I thought the tweet was fine. Twitter is an awful place to explain anything, but it got the point across pretty well. You have to be able to say that you don't like Kojima at this point, even without backing it up, without being accused of being a troll or whatever, like some people have. The "Love, PK" stuff of the next tweet was a bit much though

Anways, Kojima and GDT's involvement in the project is still very much unknown right now, from what I can gather. GDT likes to attach his name to every project in the world, so who knows about him. I'm guessing Kojima will be more involved.