Nothing officially official. There was Filoni’s
concept art and his cryptic
comment about it "making sense” to use him in the series at some point.
Personally, I’ll be shocked if Boba doesn’t end-up literally disintegrating Cad Bane. I’m sure Anakin would be appreciative of such an act.
Death Watch is definitely headed for a big-time showdown with the Republic. Given Pre’s tendency to get snippy with the Count, they may end up turning against the Separatists as well. That being said, a giant three-way Armageddon-style battle would be nice climax for the series. Preferably, such a sequence would be conducted in IMAX 3D. After all, the series began in the theaters.