The Fantastic Four are one of the first Marvel comics from back in the day, coming a year before even Spider-Man in 1962. Yesterday, Marvel announced that they intend to o back and re-write the quartet's origin story with a poster that reads ""who really gave the Fantastic Four their powers?" and gives us a a date when "Marvel history" will be "destroyed:" March 2019. Presumably this "who" means that the Four will be given their powers by a specific person, rather than the current story that has the four of them being exposed to cosmic radiation while in space and turning into The Thing, Mr Fantastic, The Human Torch and the Invisible Woman.
In terms of the Marvel Cinematic Universe (MCU), this could mean a reboot of the Fantastic Four as a movie, especially now that the Avengers series will be ending in may with the aptly named Endgame. Marvel has been trying to make Fantastic Four movies for a while now but has been doing an uninspired job. There was the 2015 attempt with Michael B. Jordan as the Human Torch, which didn't do so hot, and also the iconic but very bad 2005 edition. My only hope if they do reboot: bring back Jessica Alba!