Well, most observationalists are talking about our "global" spacetime defined by our past and future lightcones. The stuff we know occurs. Theorists tend to be a bit broader and laugh at the petty existentialism that the observationalist embraces. Just because there is a space-like rather than time-like separation for the theorist doesn't mean the event is outside of our universe. So they tend to include everything that "exists" as part of the universe, for the most part.