Yes, that's right. Guevara didn't meet Castro till much later in life (in Mexico IIRC).
Without Che, Castro would prtobably still try to land in Cuba and start a revolution against Batista (he had planned this before meeting Che). If things go as IOTL, he and his camarades would probably still be spotted, and would have to flee to the Sierra (highlands). The question is, would they still be able to depose Batista without Che? And if he does, would he become communist?
No Cuban revolution (or a non-communist one) would make the history of such a timeline differ greatly from our own, since this revolution produced inmediat effects in the stories of Latin America, the US, Russia and the rest of the world.
A Communist Cuban revolution without Che would make this TL differ a bit less from OTL. But it will still differ, because:
- Che might have had an influence in Castro's decission to bring the Russian's (and their weapons into Cuba). No che might mean no Missils Crisis.
- Che's succes was an inspiration to many guerilla movements in Latin America and Europe from the 70ies onwards. Castro might replace him in this roll in TTL, but I think he'll be comparatively less "inspirational"*...so we might have less guerrila movements in the 70ies, which would radically change the history of the countries in which this guerrillas operated IOTL.
* After all, Castro (setting aside what I think of him) is a politician in power, and politicians have to make compromises, and take umpleasant meassures. Eventually he will adopt a meassure that will end up disapointing their most fanatic supporters. Che became a myth because he left Cuba soon after getting into power, and died fighting to make the elsewhere. He wasn't "worn out" by being in power for long.