The possibility of a Spain pavilion was a pet theory amongst outsiders who kept saying Spain was the next pavilion because of Gigantic and the necessity of only building a new pavilion if there was going to be a 'matching' IP ride.
They theorized that surely WDW would open up a new ride to coincide with a new movie, right? If that's the case, then how are we all enjoying the
Inside Out ride? Or that
Zootopia ride?
Well, Brazil is the next pavilion and it's being built without an IP ride, or any ride at all (according to
@marni1971). So, the idea of "Spain + Gigantic" was always a fan theory and never an insider rumor.
Spain is rumored by an insider to be the next pavilion after Brazil (if India isn't next) according to our insiders -- and not because of Gigantic. Any national pavilion needs mostly commercial sponsorship, not a Disney movie that needs promoting. But, this is still far off and not anywhere near greenlit.
From the rumor tracker...