Yeah, in 1E-3E the world is called Abeir-toril because it's just Auld Wyrmish (the most ancient language still used on the planet) for 'Cradle of Life'. 4E rather ridiculously retconned this as that the one world of Abeir-toril was long ago split into two worlds coexisting in different dimensions at the same point, Abeir and Toril, and the Spellplague (the highly controversial 'Realms-shaking event' between 3E and 4E) saw the two worlds smashed back together resulting in lots of magical craziness such as Maztica exploding and being replaced by a new continent called 'Returned Abeir' (the current Realms writers have issues coming up with new names that don't suck).

In my Realms campaign, the Spellplague never has and never will take place and Maztica is still there