As anticipated, Flash Season 3 will start with a form of “Flashpoint.” The 2011 event miniseries featured Barry Allen accidentally changing history. The ripple effects of the Flash saving his mother led to a world where Barry never became the Flash, Bruce Wayne never became Batman, Superman was a lifelong prisoner in a science lab, and Wonder Woman and Aquaman led their nations in a global war that threatened to destroy everything.
Grant Gustin confirmed that the season three premiere is titled Flashpoint, but adds that the TV show’s adaptation “will be its own thing.”
https://twitter.com/grantgust/status/744932568106049536
https://twitter.com/grantgust/status/744951601341702144
Obviously they can’t do the exact same story in a universe that already doesn’t have Superman, Batman, Wonder Woman, or Aquaman, but they can certainly take the basics:
Flash changes his parents’ history, accidentally screws everything up, and has to fix it.
(When I put it that way, it sounds a lot more like Back to the Future, doesn’t it?)
I think Earth-1 Real-Harrison Wells is a safe bet for the altered timeline, as is seeing Eddie Thawne again. An Arrowverse Citizen Cold could be a lot of fun, as long as they don’t go the full cannon-fodder route that the comic did.
In the comics, DC used the event as an excuse to relaunch their entire line with a new history at the end. Barry fixed time, but it didn’t settle in quite the same way as before. I can’t imagine the CW will completely reboot four TV shows at once — they’ve all got way too much momentum to do that. But they certainly have the opportunity to make adjustments like they did with the Pied Piper this year. Earth-1 Wells might be able to stick around afterward, for instance, or Jesse might have an Earth-1 counterpart. Or they could do something bigger, like merging Supergirl’s universe with the Arrowverse. Or at least explain why National City suddenly looks more like Vancouver than Los Angeles.