They may try a bigger refresh than they did at the six year point, but I imagine they will keep the model names in any case.

But with such strong sales, the incentive is not to rock the boat. Incumbents refresh more often because they have a lot of competition.

Tesla does not have any meaningful competition for the Model Y. The closest competitor is the Ford MME, and just behind it the Ioniq 5. But Tesla still sells like 3-4x as many Model Ys as both of those combined.

The Model 3 has even less direct competition. But that's probably because the sedan market as a whole is not as strong as crossovers. The biggest competitor to the Model 3 is probably the Model Y. And to put some context on this -- even as a sedan, the Model 3 outsells the Subaru Outback. Anybody wondering whether Subaru will stop selling Outbacks?