Sure, maybe it can work? But if it was so straightforward to install a tundra/sequoia motor then why wouldn’t a junkyard warranty one installed into a 200? And why wouldn’t a shop warranty the labor installing it?
Good for you and those who can DIY - though I suspect you'd still have to accept no warranty on the tundra/sequoia motor?
For the remaining majority, they will be stuck sourcing expensive LC/LX motors only with good warranties which from reports here run $7k - $10k. Throw labor costs on top, and additional/continuing depreciation on the vehicle, and you have a major problem.
Shops aren't generally going to take on unknown risk based on unvalidated information requiring them to do their on research and critical thinking. There's just not a lot of information for this niche vehicle for them to go on. This would also depend on the skill level of the shop/tech to know or identify what exactly to swap over. For these shops and general customers, the risk is not worth the initial cost difference between donors.
That doesn't mean it can't work for the informed or a more skilled specialty shop.
Like @bloc , I would have no hesitations using a Tundra/Sequoia donor.