The choice of Pirelli Elect was probably inevitable for Tesla because Pirelli has fro a long time been adept at special-purpose application-specific design plus a little known advantage that they are often less expensive for OEM than ar most other alternatives. Those are not always true, but often.
With Elect my friend with Tire Business mag tells me they went all out, intending to capture Tesla Performance versions, Porsche plus the odd Rimac etc. Usually she knows what is happening, not perfect, but better than anybody else.
Somebody else was told 'summer tires but all season use' so I asked her about that bizarre statement. She claims that Elect summer tires still have resilient compounds so have much less low temperature sensitivity than do 'normal' summer tires.
As I said, I cannot say that is 100% true, but it seemed consistent with all information thus far.
It's curious that the 21" seem not to be Elect. Is that true?