So it turns out that tease from Marvel Games involving the number 4 was related to the Fantastic Four after all and it looks like it'll soon tie into Insomniac Games' PS4 exclusive Marvel's Spider-Man.
As part of its Fantastic Four Week celebrations, Marvel Games announced that the team of heroes is coming to its various games. I can't tell you anything more right now, but you'll want to keep an eye out for this. "While they may have awesome powers and go on wonderful journeys into the unknown, at their heart the Fantastic Four are a family who may argue and bicker from time to time, but who ultimately stand with each other to protect the world against the universe's greatest sci-fi threats".
For starters, this could finally see the arrival of the Bombastic Bag-Man costume from the issues of The Amazing Spider-Man finally appearing in Marvel's Spider-Man.
On top of that, a "new Epic Quest has been added to the game, focusing on Mister Fantastic".More news: Highlights From The 76th Golden Globe Awards
The most popular theory is that one or more Fantastic Four spidey suits are on the way.
"Spider-Man has a long history with the Fantastic Four and even served as a member on more than one occasion".
Given Insomniac's sense of humour, my money is on the infamous Bag-Man costume that Spider-Man had to don in the comics.
So although we don't know the what's, where's and when's of this new addition, we can make educated guesses that it could be a DLC adventure add-on, maybe a new suit for Parker, or some third thing. Split into three episodes, the City Never Sleeps DLC also re-introduced Black Cat, Silver Sable and Captain Watanabe into the story at various points too.