Ah yes, forgive me. I completely forgot he was in Dobby's release, and forgot the new Diagon Ally completely. Thanks for reminding me!
Hmm... I never saw the Prince of Persia, and my knowledge of Pirate of the Caribbean is spotty at best, so I'd have to go with the Ahsoka/Star Wars comparison. Whilst those Death Eaters are relevant, I just don't see any distinguishing features that warrant them being made into figures. The Malfoys (besides being important enough to be made) have the pristine hair and facial features, Fenir is a beastly looking individual, and Bellatrix looks like a Gothic Pride, similar to how all of the Star Wars alien Jedi (Fisto, Mundi, Koon, etc) were all made because they're recognizable. The other remaining Death Eaters (Pettigrew excluded; he was dead by the battle of Hogwarts) would likely seem rather bland and uninteresting by comparison; there is little to separate them from the crowd.