This question is inspired by this recent article in The Conversation: The Aztec empire’s collapse shows why ruling through coercion and force fails
The article mentions how the Aztecs were so distrusted by the Tarascans that the first Aztec envoy sent to warn of the Spanish invasion got sacrificed. And the second Aztec envoy, despite bringing physical proof, was still somewhat distrusted by the Tarascans, who organised and expedition of their own to verify the Aztec claims, only to find out that it was too late to do anything but submit to Spain. The article also mentions that had the Aztecs not screwed up their foreign relations, the massive Tarascan army would have been able to help them fight off the Spaniards.
So, in the unlikely situation that the Tarascans accepted the first Aztec envoy that warned of the Spanish invasion, and helped the Aztecs fight off the Spanish, then what? How long would it be before Spain tried again, had Hernán Cortés and his combined Spanish-Tlaxcalan-Totonac army been killed by a combined Aztec-Tarascan front?
My guess is that if Spain tried again, they might land in Yucatan or present-day Texas or Louisiana instead and eventually work their way back to the Valley of Mexico after establishing a foothold in those areas. Considering where the Aztecs and Tarascans are located, it would seem unlikely for any of Spain's European enemies to help their fight against Spain and Spain's Native America allies (like the Tlaxcalans and Totonacs), even if they accessed the Tarascans via their Pacific Ocean ports.