im pretty sure that sweet pea never gave up the movie rights that warmer and Hasbro were trying to sue to acquire back, and that's why sweet pea is co-producing. I also don't believe Hasbro is going to give up the rights to the D&D brand. That's actually the most valuable part. The rpg just sustains the brand.
I actually hope that the movie is Forgotten Realms branded, maybe with D&D called out in some sort of logo like the MCU uses. D&D and FR are not equivalent and trying to make them so is a huge mistake, IMO. Why would you limit yourself by tying it all together, when you could do a Realms movie or series, an Eberron movie or series, a Planescape movie or series, etc?
Really, I could see Eberron doing quite well on the big screen. It could be done in a very visually stunning way that would be very different from, say, LotR, but still a ton of fun -- think more
Golden Compass mixed with
Indiana Jones. Planescape might be something of a modern
Fifth Element done by Clive Barker or Tim Burton, but I'm not really that familiar with the setting. Even Ravenloft could be done as something resembling
Underworld, though I'd rather see it with just a bit of actual horror.
Regardless, those would be very, very different movies than a Realms movie based on, say,
Princes of the Apocalypse. All could also be done well, too. You just have to know what the brand actually is (and have good writers, actors, and budget, of course).
My one request for Hasbro is to please keep Michael Bay away from this IP.