This was revealed in a series of tweets that talked about the delay and potentially disappointed fans.
A big thank you to everyone playing MultiVersus. It’s exciting to see so many players enjoying the game and the launch of the Open Beta is just the beginning.
We want to let everyone know that we are delaying the start of Season 1 & the release of Morty to a later date. We know this might be disappointing for some and want to assure our Community that we are dedicated to delivering new and exciting content that delights players.
We’ll let you know the timing as soon as we can. We appreciate your patience & enthusiasm and look forward to unveiling Season 1 very soon!Twitter
While no reason was officially given, many speculate it has something to do with the ongoing Warner Bros. Discovery merger. Just yesterday the Batgirl film was canned, along with a number of other programs and speculation HBO Max might become part of Discovery+ among other things.
Update: Huynh confirmed this delay is unrelated to the Discovery merger.
Another possible answer is pushing back the first season over reception of the current open beta. Several have expressed concerns about finishing the first battle pass, which includes some notable items like a Cake costume for Jake, Lasso ring out and a few amusing taunts. Another tweet confirmed the initial Battle Pass will continue until Aug. 15, though no comment on what happens after that. Along with that, several people have questioned the hit boxes, something that is apparently in the works. It’s also possible other quality of life improvements will go into the official release and because they don’t want to further disappoint fans, no release date was given,
Regardless, we will find out the answer sometime in the future and if you haven’t taken the chance to experience MultiVersus, now might be the best time.