Teslas european pages still show that model Y production is supposed to begin early 2021.
I doubt they're going to import any model Y:s.
Then we need an alternate explanation for the jump in Model Y delivery time.
Perhaps they are stopping the line for a few weeks in October to retool for the stamped back end. That would mean Y sales would not increase much in Q4.
The best argument against a model Y surge to Europe is that Tesla doesn't have the additional transport capacity. They want to sell more cars, after all, not just replace sending model 3 to Europe with Model Y. Could China be sending ~10K Model 3 to Europe Q4, thereby allowing Fremont to send Y with no increase in units shipped from the U.S.?
Also, would it be beneficial to only send a few thousand Y's to Europe? Would that Osbone Model 3 sales? Or would it encourage model 3 sales by allow European consumers to see both cars? Certainly there are potential buyers waiting to see both cars. I think many will find that the Y is considerably bigger in the real world than in photos with the 3. It's not a 3 with a somewhat raised roof and a hatch.
It doesn't feel right to me that Tesla will sell many more MY in the U.S. this December than they did in September. But I have no way of knowing if Tesla is seeing a significant acceleration of MY sales since August.
I also think that Tesla really wants to recapture that $3000 discount on the Model Y. Their price point strategy from the M3 SR on up seemed right to me.