The Kelvin timeline doesn’t have to play a huge role, but a small acknowledgement of it considering it’s tied to canon would be nice.
I can’t imagine Star Trek: Picard will journey to the Kelvin timeline (if that’s even possible), but I would wager there will be at least one reference to Ambassador Spock’s disappearance.
It’s the perfect way to pay homage to Leonard Nimoy’s final performance as Spock without needing his actual character, and will have to be referenced anyway considering there are clearly some off-world Romulan survivors that have lived as refugees.