This seems to be an unpopular opinion among the American monomyth enjoyers, but

I don’t think Luthen and Kleya “have” to die. I don’t think characters that we don’t see in the OT have to die. I don’t think that characters who have done questionable things for the rebellion don’t get to experience and participate in rebuilding the new, better world, and heal together with the more pure of heart characters. Luthen has been cut out of the chain of command, and there’s no reason he can’t have continued to be a spy on Coruscant or something through the war. The rebel life he leads is one of the riskiest of all the people in the rebellion, but it would definitely be a nice subversion of the cowboy trope for the guy who’s sacrificing everything for “a sunrise he knows he will never see” to actually be one of the few OGs that do get to see that sunrise in the end.

As for Dedra, I think she finds out what they’re really doing with those rocks, and I don’t know what’s going to happen, but probably the obvious thing would be for her to eventually be posted on the Death Star, right?

Anyway, I agree with all the praises of the show’s nuanced writing and music and stuff, obviously. There is room for different genres in Star Wars, but I do miss this level of subtlety in other shows (namely whenever Filoni does a politics-related plot or whenever anyone but Zahn writes Thrawn…)