IMO, yes. It does seem like that battleship has kinda been sunk. The impressive thing wasn't predicting Re:Mind itself (we knew about that since September), but was predicting the delay to January 2020 and a Game Awards Reveal, as these details seemed to be correct.
However, given that the Re:Mind trailer was unveiled at State of the Play and the January launch date only applies to the Playstation release (hinting it was more of a lucky guess than legitimate knowledge), I don't see why we should give this leak anymore attention than a standard 4chan greentext.
It kind of reminds me of the way people were tripping over themselves to analyze the Gardevoir leak because it predicted Richter, when it failed to predict anything else that happened in the August Smash Direct. Smash leaks on 4chan are basically the product of a bunch of monkeys with typewriters: there's so many being produced with such minor differences that it is almost guaranteed they'd get something right based on pure probability.