And if Columbus had never sailed the Ocean Blue, the New World would have still been found by Pedro Cabral of Portugal.
Portugal was concentrating on the prize at the time, a sea route to Indies/China. The Spanish would have gotten here pretty quickly and after 700 years of the Reconquista were uniquely prepared to take on conquering a continent or two in the name of God. Glory and Gold were good too.
Sooner or later the "discovery" was going to happen.