I wouldn't be surprised if it's a new X-Men series altogether though. Disney will probably want to make a new X-Men animated series for the service at some point, and what better way to announce it than by saying "From the visionaries behind X-Men: TAS..."?
The fact that they were pitching a revival series to Disney a few months ago, and are now working on something new, tells me something's up. Hopefully we get a new series *fingers crossed*.