Google says 4250 mm is 167.3 in. Toyota USA has the Supra at 172.5 in. If true, the Supra will be 5.2 in longer than the GR86.
https://www.toyota.com/gr-supra/features/mileage_estimates/2372/2374/2375
Old article, but if that's still Toyota's plan then ending production of the A90 in 2025 makes sense.
Toyota says all its cars will have an electric or hybrid option by 2025
https://www.cnbc.com/2017/12/18/toyota-says-all-its-cars-will-have-an-electric-or-hybrid-option-by-2025.html