This is probably all much ado about nothing. Toyota's hybrids and PHEVs are selling as fast as they can make them. The only reason their sales numbers aren't higher in the US has been lack of parts! Cannibalizing the rare materials they could use to make their very successful hybrid lineup in order to make fewer/less profitable/less impactful cars seems pretty foolhardy.
Toyota's entire MO is to take old, trusted technologies that they can refine through manufacturing. Even as innovative as the Prius was, it was not a slapped together car to meet market demand. So I find this entire framing fraught.
I think the only warranted criticism of their current strategy is that they have not been aggressive enough about locking in battery suppliers. If Toyota wants to proceed down their current path of making every car in their lineup an ultra-durable 300k-achieving hybrid, they need to make sure they don't get bottlenecked. Every other manufacturer is locking in exclusivity deals with battery manufacturers, and Toyota still has a lot of scaling up to do.