My understanding is that technical information is translated for every country to provide information for the dealers, as they have to service the cars. I know for instance that there is a Dutch version of the FSM, but it was never available to the public.

Maybe MB USA made some kind of deal (with ATSG for instance) to limit the information about transmissions, you can imagine it can have some commercial gain.

Most dealerships don't do complicated stuff such as IP adjustments or transmission overhauls. They use specialised companies, so the need for information about the transmission for the dealer was also limited.