I am truly surprised at finding new things still in Tokyo. I also think that PD aren't telling us something, as the lighting seems a bit different from the usual pre-baked. Maybe as they set the time of day for the seasonals, they have a time change version of R246 in the works...
Could be just me though.
I've come to a similar conclusion - R246 may have a time/weather change version coming in GT7 (the most probable scenario) OR it could be that PD are working on making use of the other roadways we can see around R246!