I think that in any other game crossplay would not be so difficult to implement (even now there are games that have it working), but since its Frontier we're talking about I can see some problems. Then again not bad enough problems that a patch, or two, or three wont fix...
Anyway, good points about would crossplay enable multicrew etc. between different platforms. Maybe it can be improved overtime, if at first its just so we can see and interact with each other in the most basic ways.