You can have some of mine!
I've had so many that I've lost count. I honestly don't recall if I had any after completing the Imperial Legion quest line but I definitely have had Thalmor patrol ones afterwards. I've also had Imperial patrols with the same prisoners which reinforces the notion that there's a Stormcloak affiliation factor for people being arrested by the Thalmor.
The random nature of world interactions while traveling in Skyrim and the variety of them can make for a very different experience for each player. For example, I didn't see any Thalmor Patrols at all after completing the Stormcloak quest line, but the game data doesn't support the notion that completing the quest removes that world interaction from the game notwithstanding that it makes sense (which is why my proposal to add a note about it on the UESP World Interactions page got shot down by the admins
). One of the admins pointed out that in all the hours he's played the game, he's
never gotten a dragon encounter inside a capital city nothwithstanding the fact that they definitely can occur.