How the hell do you create such a good miniseries, and then absolutely obliterate it by ending it that way?!? I feel as if I've never been more disappointed.
I am a massive fan of the canon Thrawn novels, so when I heard Alliances was going to be a comic, I was excited. I loved the first three issues. However, there were mistakes.
The first mistake I noticed was during the scene where Anakin and Thrawn first meet. In the books (Thrawn: Alliances, but also Thrawn: Ascendancy Chaos Rising) Thrawn is NOT piloting the ship. A sky-walker and major character of the Ascendancy series, Che'ri, was. I don't even know why they would change this, as it was not at all necessary. 
The second mistake I noticed was when Thrawn told Vader "Few have ever encountered the Grysk" when one was his enemy during his time in the Chiss Expansionary Defense Fleet. Do you forget your enemy, who tried to destroy the Chiss by nearly instigating a civil war among the Families, is a Grysk?
And then that ending. Who ends mid-story with "The end?"??? I am severely disappointed. All the questions I would've had if I never read the book would have been left unanswered. I don't care if you want to continue this in another miniseries. It's just ridiculous.