Overwatch is currently in Season 2 of its ranked play, yet Blizzard have not made any official announcements regarding an actual pro league. So the announcement may appear confusing to some regarding this statement, since the majority of the time the developers prefer to keep their cards close to their chest. Activision Blizzard are no strangers to the eSports stage, having announced the formation of a new eSports division themselves last year.
Its likely that since Overwatch is still relatively new, that they will be waiting for a few more seasons before looking into entities such as pro leagues. This will give them time to fix any issues that may be knocking around before building a foundation on what could possibly be one of the most exciting eSports leagues we’ve seen so far.