My car is back at the dealer this morning as well. They didn't give me much information on what exactly they were going to do but they gave me a loaner. They did know it was going to take more than a day to fix and that's why I got the loaner.
Just to recap, I've had TSB12B37 done, had the clutch actuators replaced and still the issue persists with the shuddering. I had to come back and take a drive with a mechanic to prove that the shuddering exists.
I'll update again once I hear back from the dealer on what they're doing and when I'll get my car back.