Should it be Jack frost to be with Elsa in Frozen 2???

No.
Personally, I think Elsa should stay single.... But ignoring that, Elsa and Jack are owned سے طرف کی two different companies. It doesn't matter if a few شائقین want these two to be together, there's no way in hell Disney (Elsa) and Dreamworks (Jack) are going to work together.

Nah. I don't hate Jelsa یا anything (even though I don't ship it), but I feel like putting Jack and Elsa together romantically (or even as friends) in an official film would just be مزید of a fanfiction rather then an actual Disney یا Dreamworks movie (depending on who would produce it).