It’s like the USA confiscating Russia’s US dollar assets - you do it once, and it puts everyone else on notice you are not reliable, and should look elsewhere
if it is like everyone else, it is proprietary software, usually running on a PC modified in a proprietary manner to be a local server (each local server may forward certain requests to a central server at corporate HQ). the local server talks primarily to a diagnostic module on the auto itself.
without diagnostics and status resets, IMHO a modern auto quickly becomes unreliable to drive. it seems possible that the auto becomes dangerous to drive.
the charitable thing for MB to do at a minimum would be to release the software protocol between the auto diagnostic device and the local server (IIRC the hardware level is common to all modern autos via a standard). however, if MB does this then it opens the portion of diagnostics that runs on the local server and corporate server to its worldwide market, which could then come up with server clones that could (would) drastically reduce MB service revenue. each local server could cost US$40K or more (2012 US$, the significance of 2012 being the date of the last time I tracked it).