I have mixed feelings about this book. It was cool, but I don't think it was memorable. It does have a clear plotline in counterpoint to the previous two, which made the experience more seamless, but the end result wasn't nearly as interesting.
If we didn't know of Thrawn's eminent fate in Rebels, the story would have no stakes; and was left with little answers. Even with incoming projects, the trilogy should stand better on it's own.
That being said, seeing Eli again was amazing (even if severely lacking interactions with Thrawn), and I'm always interested in the inner workings and expansion of the universe.