I already said its a reboot in the sense of Sony's attempt to update the Spider-Man film franchise and leaving the story of the first trilogy. So we start from scratch here. The story still follow 80-90% of the original comic book that began with Peter having Gwen as his first gf. In the past trilogy, the story began with MJ already and Gwen still alive in the third movie, very much the same setup with Lois Lane and Lana Lang in Superman. MJ will probably come later (in the comics, she is a close friend of Gwen) when Gwen says bye bye... That is, if the screen writers decide to stick to the comic book story..