I thought the finale was great. Though it seems simple after the fact, I never thought about them not making Ashoka a Jedi any longer as a way-perhaps-to give a logical reason why she isn't in Episode 3 or talked about in that film without killing her off.
Similar to bill cosby I also felt like this finale could've been a series finale. I know it isn't, but if it was, I would be pleased with it.
Not so sure how I feel about Barriss Offee being the traitor. I thought that was a bit too obvious, though with only about 20 something minutes, there's only so much you can do. I was surprised by how good Offee was with a lightsaber. She was holding her own against Anakin. It was also nice seeing some of the younglings from earlier in the season.
I thought her rationale was muddled. Before fighting Anakin she says something like the color red (of Ventress's) lightsabers suits her, but then before the tribunal she talks about the Jedi being consumed by darkness.
I also thought it odd that Palpatine would be sitting in judgment of Ashoka. Not feeling the new voice actor for Palpatine either.
But overall, I thought it was a great ending for the season. It will be interesting to see if Ashoka comes back to the Order in season 6 or if they do something else with her.