I'm going to disagree with you there. A different direction yes but a better one? Problems introduced in KOTFE/ET such as killing companions and character waste are still present. Take the dark council members from Onslaught for example - Four (Five if you include Malora from JUS) dark council members can be killed off within a short time span making them look weak and wasting their characters for anything that could happen in the future.
While I'd love a story. I'd do Clone CM companions (like the Pets and Droids) and then let players who want her as a companion be able to do so through that.
Oh wow. the only Vaylin mod I was aware of was for Jedi Knight: Jedi Academy. I might have to consider getting Battlefront 2 now.
You could also have Senya sacrifice herself by transferring her life force into Vaylin.