Joint venture with BMW, lots of BMW tech, so not a “natural” Supra just like the ft86/fr-s is a joint venture with Subaru, people call ‘em a Toyobaru around here :).
I'm reminded of the "GNU plus Linux" copypasta.
It's not just "lots of BMW tech". It's literally a restyled Z4 with the same German engineering quality that will fall apart in five years. Toyota throwing them money doesn't change who really designed it.
Imagine if they rebuild the mark 4 with carbon fibre and an electric drive train.