The question is will they use the same engine to be sold in the US or will they use, for example, the new 1.8 turbo from the Levorg? I've seen on this site mention of the GR86 being sold in Spain but the BRZ being sold in Australia. Of course when the original car came out it was sold as the 86/BRZ in Europe, the BRZ Scion FRS originally in the States. So Subaru saying the BRZ will not be sold in Europe may be a correct statement. But this says nothing about the 86. Being that Toyota may be more of a worldwide company it is easily conceivable that it would be sold in other markets. Further it is conceivable that they could use a different engine for other markets for emissions compliance.
Who knows maybe because they are calling the Toyota version the "GR" 86 they perhaps could fit the new 1.6 turbo from the new Toyota Yaris into the engine bay. As of now we have no idea if the engine bay is the same size or large enough to fit an inline four cylinder. The profile of the car seems to indicate a higher but longer roof line that slopes down at the front. So perhaps maybe there is room for an inline four cylinder turbo. I've seen a few video reviews of the new GR Yaris and they have been positive. That would be quite interesting but I guess that would not be offered in the states. I assume I am wrong as the engine bay size has probably not changed much as it is on the current BRZ/86 platform.I'm assuming that the 1.8 turbo from the Levorg is a physically smaller engine than the 2.4 engine from the Subaru Accent. If that is the case there may be enough room for the turbo 1.8 to fit. Of course this my mere speculation. I will say that so far Subaru/Toyota have done a good job keeping us in the dark.....