Didn't @A70TTR also said it was going to be B58 base? Anyways, iirc both of them more or less stated that the only minor changes were happened due to the fact that Toyota will be focusing the majority their resources on the next A100 Supra.
There was a post awhile back that said Toyota has two versions of this "MR2" concept. An EV as we have all seen and an ICE version that has not been shown to the public. I'm hoping the latter is the one that gets approved.