The tippy part is they go off the OG lore so Cyrodiil is a more tropical/Mediterranean climate which is fun.

Fucking Thalmor denying the power of Talos of Atmora.

Seriously though, the canon explanation for Cyrodiil being the way it is now as opposed to original lore is that when Talos achieved CHIM he changed it, because that’s a thing you can do with the secret syllable of royalty. All part of the path to mantling Shor/Lorkhan via one of the Walking Ways and forging an empire.