There are no other details shared, and I didn't watch his Funko appearance. /Film just pulled out that bit about D&D.And while Manganiello couldn’t get into details, he hinted at Funko Hollywood that there would potentially be more Dungeons & Dragons collaborations in his future. “There is something in the works right now that would take all of my attention and time,” he shared.
We do know that Joe is a huge Dragonlance fan. Once upon a time Manganiello was working on an unapproved script based on Dragonlance. That script was presumed dead, because it certainly wasn't attached to the movie coming out some day.
We also know of the Derek Kolstad streaming project that seems like it centers on the Underdark, but maybe not. We know that Andrew Cosby is also working on a D&D streaming or linear TV show, probably not the Kolstad one. In past calls Hasbro has said that eOne is working on one movie (that big budget thing everyone knows about) and has used the plural when it comes to episodic things like streaming or conventional TV.
While it is possible that all of these people are on the same project, this seems highly unlikely. The era of D&D as a media franchise seems just around the corner.