So I was wondering if the Toyota 86 GT was named something else (maybe Scion FR-S?), or was it named Toyota 86 GT, just like what other places' names are?
The Scion FR-S is based on the same car, but it's a different car. The Subaru BRZ is based on the same car, but it's a different car. Only the Toyota 86 GT is in the game.
As far as PD giving us the frs and/or brz as well is unlikely. All three are more or less the same car with minor differences. People might complain that PD is making more "duplicates". Possibly in the future (GT6?), but PD should be focusing on other things right now.