It'll come out two weeks later - on June 7th - and the devs say it's because they want to polish up the online and action feedback from the closed beta.
"To support the Social Play features, we are using a brand new online technology. We also want to make sure we have the opportunity and time to address player feedback from the Closed Beta. That is why we will give ourselves a bit more time to perfect the game, with a new release date for Mirror’s Edge Catalyst of June 7th (NA) and June 9th (EU). We’re confident that these extra two weeks will make sure the game is as amazing as possible for you the players."S'cool, s'cool. We're gettin' Mirror's Edge 2, that's all I need.