There is no reason for the writers to bring Jason back no matter who was playing the role. TPTB want KM and ME together and they want to have Carly and Franco develop some kind of relationship(friends or lovers) bringing Jason back now would spoil all of those plans.
I do not think Jason will be coming back for a bit of time yet. Silas and Sam have to get all hot and heavy first. Then deal with my daddy is a resurrected mobster, and start a walk towards the alter. Then I think old JJ will be back in town. Or at least someone claiming to be.
I'm fine with Jason staying gone for the foreseeable future and I used to love him. The stories that involve his main acquaintances are moving along great without him and I think a return for him would disrupt the current flow. Not to mention that it would still be hard to see anyone else in the role and I don't see SB returning anytime soon.... if ever. :~