Yeah, pretty much.
Basically gives him the ability to look the Thalmor in the eye, shrug, and say, "$&#% if I know. I had no clue what they were up to, since, you know, I fired those guys weeks ago. Kinda sucks about them siding with the Redguard resistance and kicking your asses out of Hammerfall. Well, good luck with it. Hope your forces doen't get slaughted by die-hard warriors and highly trained ex-Legionairs."
It hurts the Thalmore, keeps the Redguard as a secret allie, and buys the Empire a bit more time to recover. Pretty brilliant, actually.