The announcement of Rey Mysterio in the upcoming WWE 2K19 Video Game likely means that a deal between him and WWE is imminent as the track record of wrestlers like Sting, Goldberg, Ultimate Warrior all ended with them signing.
According to Dave Meltzer in a recent edition of the Wrestling Observer Newsletter, an agreement between the two sides is expected to happen in “relatively short order” and when it happens, WWE will likely be the ones to announce it on their website and social media as they very much want to be the ones to break the news.
Source: Wrestling Observer Newsletter