I just want to weigh in real quick on the whole "truck engine in a car" discussion.
It could just as easily be seen as "a car engine in a truck". Look at what Chevrolet does with the
LS Small Block. Some people might be surprised to learn that the Corvette doesn't use a unique engine, but by using the same engine block that they use in their trucks and SUVs they're able to keep production costs down on the Corvette. Obviously there is a shit ton of differences between the engine and tune on the Silverado compared to the c7, but the bones are the same.
The whole reason the twins exist is Toyota didn't have the budget or target market size to justify designing, engineering, and producing a performance engine specifically for use in a sport coupe.
It's perfectly reasonable to see why they would put the FA24 in the next gen 86. This will allow them to keep costs down, and get a power increase without going FI. As much as I hope they'll offer a turbo version from the factory, I highly doubt it now due to the release of the 4-cylinder Supra hitting the US market. I just feel there's too much overlap there, having two four-cylinder turbos to choose from in the same lineup both with very similar target demographics.
Someone should really start a poll so we can all place our bets.