Coil Coupler’s site seems to indicate that there is some sort of 2 way communication happening. They state that all Cab2 running on a layout will display all current information for all trains running at that time. You can set the spped of an engine using remote 1 at 55 and if you address that same engine on remote 2 the readout will read 55.
Also it seems that the memory modules can also be dumped to with engine ifo so you can take that info to another layout and Cab2.
This is exciting news to me. Seems there is some more cool stuff coming out of TMCC2