I would think the Ezra-Thrawn thread would be picked up in other media for a resolution. However the effects of said resolution could impact Resistance at some point.
It is not outside possibility that we could see said characters, but I don't think we will see the resolution of the cliffhanger in Resistance, just its aftermath.
I am fully prepared to have Thrawn be part of the First Order, or even be his own thing (returned to his home systems to defend them from whatever is coming), or part of the legal remains of the Galactic Empire, rather than the illegal First Order. Ezra could be training Jedi in the Unknown Regions, or he could go the Ahsoka route and be a non-Jedi who is still basically a Jedi...thus allowing for another path that is not the Jedi or Sith, nor the path of Kylo Ren. If Ahsoka is still around, she's be in her late 60s. Not that that might mean much for her species.
The rest of the Ghost crew may or may not have any meaning for the story. Zeb's probably gone by now, or retired with his people. He'd be in his 70s. Hera's in her late 50s or early 60s by now. Sabine's likely in her late 40s or early 50s. Erza, assuming no time travel shenanigans, would be in his late 40s. Rex and the remaining Clones should be died by now, as their bodies would look like they are well over a 100. Chopper.....is a droid, should be still be annoyed at life, but he has hobbies and working with the Syndula clan. If the Ghost itself is still operational, is could be the best freighter out there right now, since the Falcon is, well, out of commission.
Depending entirely on when in the timeline the series starts. The Resistance started roughly six years before the events of TFA it seems. Poe was born during the Galactic Civil War, thus would be of combat age in the New Republic at least seven or eight years before the Resistance forms. His story about finding out about the First Order has been told, and that was after the Resistance was formed (I think). So I don't imagine the show will start too much before the events of TFA. No more than five years, and probably closer to two years as imagine they might want to attempt to tie in this series with Episode IX after the end of next year. Other Resistance groups and all that.
