Superbit is not for the Region 3 only, It's an internatinally lauched series.

However, It's a Technically enhanced version DVD of "Columbia TriStar Studio", that means "Superbit" is a franchise of Sony, so only movies from Sony studio have the possibility to be made in "Superbit" standard, and be released under the name.

So as for the instance you mentioned before, "T2", Since it wasn't a film from Columbia studio, you'll never get it in Superbit.