SimRail hasn't gone on sale yet, so we don't know whether they have any licenses for their rolling stock/stations yet. We have only seen very early development shots, and it is absolutely no surprise that these are unbranded. Given their connections with real railway industry, at a professional level as a real supplier to the industry, I think there is a fairly good chance that the SimRail guys will be able to negotiate any relevant licenses they want - and I suspect that these are already in place, and were put in place long before they started coding. But you are right - if the trains are unbranded, then they will be very much less attractive. It seems that quite a few companies have been able to get branding, so it would be a very big surprise to me if the SimRail guys fall at the last hurdle on this issue, whereas all of the others have been able to get what they need, as if by magic.