Out of deference to the position potus, I assume all living current/former presidents are invited to such events.

But Will They All be Invited in hopes of having the hugest turnout ever? Or shunned?

Trump doesn't exactly scream "deference" though, does he? I would push back on the notion that all would be invited. If he believes that Biden stole the election from him (obviously false, but still,) or if he wants the public to believe that - why should he be invited? Same will go for Kamala if / when she wins...

That's not to mention the question of whether they are all healthy enough to go, or want to go. It'll undoubtedly turn into an "appearances" thing - does it look worse to their voter bases if they turn up or not?

NO feels like a safe bet to me...