IIRC, you have to have a playable build to get ESRB rating, so I think PEGI should be the same. ESRB doesn't rate games that don't exist. Usually games get released in less than a year after they get rated.
There are tons of options for Atlus to remaster and yes, Digital Devil Saga should be at top of the line. Personally I can't decide what I want from them. DDS and Devil Summoner collection would look awesome in HD but I also want some VanillaWare games on my OLED. The recent ones, Muramasa and that PSP game we never got: Grand Knights History.