I have the same theory. Only competive advantage Toyota has right now is thin margins through massive scale (and thus relatively cheap prices) and reliability. First point is not yet possible with EVs and reliability may not be as big of an issue anymore with EVs.
More complicated the drivetrain the better for Toyota since not many can make it reliably at scale. EVs seem to be fairly easy to make given how many startups are popping up.
My unqualified opinion is you’re trading one set of problems for another. With combustion you have a lot of parts under stress for a long time. With EV you’re dealing with battery science and seemingly intractable supply chain problems.
More complicated the drivetrain the better for Toyota since not many can make it reliably at scale. EVs seem to be fairly easy to make given how many startups are popping up.