FWIW, all TSB's are internal, and they are very different than recalls.
All recalls don't have to be public and broadcast on the news, but owners have to be notified at least by mail of a recall. Recalls, by the way are for safety issues.
TSB's can be about anything - notes to technicians about how to fix something, parts changes, yada yada yada.
Mercedes should've taken care of this problem, though, once they knew there was a problem. They've created so much bad will among owners for this expensive, unexpected, and unusual failure.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".