Hollywood chatter isreallynegative on this (Josh Trank got fired from his next job directing a Star Wars spinoff already), with a bunch of reshoots to try and turn it from the original product (basically a big budget version of Trank's Chronicle (Oh god, we're all freaks now)) to something resembling a more traditional superhero storyline.
I don't know if the low hype level is a product of Fox thinking they had the month all to themselves (before Ant-Man turned out non-disastrous and M:I5 moved in), assuming this is a disaster and limiting the ad budget, less than fond memories of the original FF movies, or just general superhero fatigue (this'll be the third Marvel-based movie this summer already) - I assume a bit of all of the above.