Berk's Forumvine

An interview with Dean DeBlois and Brad Lewis where Dean explains why Drago was cut out from the third film:
https://www.youtube.com/watch?v=myjCeN-RCKk

Have seen the interview yet (I'm on a mobile connection right now) but, really?

They're just going to cut Drago?

I'm disappointed, DreamWorks.

I think his explanation makes sense and I'm glad that he sacrificed Drago for the sake of the story. It's really hard to just discard something that you've had in your head for a long time and admit it doesn't work. I'm glad that they were able to recognise that and I trust the Dean has a much stronger story as a result.

I'm a little disappointed that they cut him given that he was going to get more development, but I agree that Dean made a good decision in scrapping him rather than telling a story that would've been too long or out of place. At least there is a motive behind it and he recognizes that the story shouldn't just turn into a rehash of HTTYD 2.

Yeah, I'm really bummed that we won't see the "complex character" we were supposed to be seeing, but I'm glad that he'd rather tell a good story, even if that means cutting stuff out.

I didn't take it as Drago being removed from the film entirely...his character just wouldn't the same line/development as Dean originally envisioned.
His voice actor is still on the cast list and in the trailer we see 2 sets of ships...one with Grimmel's crest but the others with Drago's.
Either he appears, both team up, or Grimmel over throws him and takes all he has.
Although sad and a bit dark, killing Drago off would also be a quick and effective way to keep him in the film but get out of needing to fully develop his character.