Assuming Italy survives as a fascist state and creates a bit of ideological breathing room with National Socialism (perhaps Germany becomes Strasserist?), a postwar world could potentially see a small Latin fascist third position block anchored by Italy, Portugal and Spain, which would likely serve as a point of contagion to allow the spread of corporatist fascism into South America. As for the future of the economic system, fascism as a class-collaborationist ideology would likely serve as an ally of the First World capitalist bloc in South America/Africa as a more palatable alternative to communism in those regions, which would give corporatist regimes something of an aegis to operate under. Yes the hardcore free-market capitalists in the US would oppose governmental meddling in the markets in the fascist bloc but I think to most people the idea of an ally sphere where the government and big business work together to battle communist subversion would make perfect sense in the Cold War period. If the Soviet sphere of influence still collapses like in OTL corporatism wouldn't survive the end of history or whatever due to simple inefficiency but the existence of an entire adjacent alliance system would cause a lot of butterflies.