There's zero doubt that Dracula should be 1.66:1 (standard for England at the time) and little doubt that Frankenstein should be anything but 1.66:1. Hammer's press releases at the time stated as much. Here's Hammer's blog on the Dracula aspect ratio: http://blog.hammerfilms.com/?p=335
It'll be fun to see the original Japanese reels and comes as a nice bonus. I wonder if they'll have the original Japanese sound? That'd be cool. Unfortunately there is still some cut footage that would have been present in the Japanese print if it were not so deteriorated. It's likely this footage is forever lost.
It's nice that they're offering two version of the film even if it's rather unnecessary. I think they got bit hard on Devil Rides Out and wanted to be sure to cover their bases here. But horror fans will never complain about censored footage being added back in.