To expand upon the last comment, Thrawn is really a nothing burger ultimately.
Why?
This show is set between the OT and the ST.
Thrawn is clearly not a problem to the galaxy at large in the ST (not even mentioned once).
So basically Thrawn and his crew come back from some nether reaches and are quickly put down in Season 2 or the movie that ties these all together.It could work if we see the New Republic being more competent than in the ST, then Thrawn shows up and wrecks it to the point that they’re weakened and willing to look the other way instead of engaging other threats like the First Order.
But I’m not holding my breath.
That’s what they’re trying to do. It’s that old thing about “The Clone Wars show fixes the prequels.” They want to repeat that concept. It’s similar to how a lot of deeply misguided fans want Mara Jade introduced so that she can get killed off to “explain” why Luke is unhinged and depressed as of the sequels.
Though I don’t think they’ll make the New Republic more competent like you said. It will be more and more of this obvious incompetence.