Square Enix have erected a 25th anniversary website for the SaGa franchise. The site will go live on February 19th and appears to be hinting at a collaboration of some sort.
In January, SaGa series creator Akitoshi Kawazu shared at a concert: “I hope to be able to make an announcement of a new title within the next two years. Development itself is quietly in progress at the moment, but we’re not at the stage where we can make announcements at the moment.”
With that in mind, do note that this may not be the project Kawazu was referring to at the time, as it sounds like the next major SaGa game is fairly early in development.