LOL
Recycled engineering to meet MPG mandates? Come on...
Toyota has vehicle refresh schedules that vary in length, and in this case had been put off for a bit longer than we all wanted. Toyota uses global platforms to "recycle" R&D achievements and lower vehicle cost while maintaining quality. They "recycled" the V6 from the LS500 because it performs very well, and since its already been in market hopefully concern out there about "not buying the first model year" of a brand new product due to quality issues.
The frame on tundra is identical to the LC300 aside from the center section of the 300 series (to account for wheel base), which is a whole new frame design and manufacturing process that currently no other automaker in the world does. Increasing stiffness by 20% while also reducing weight by 10% compared to the previous frame.
All the "recycling" that has occurred to build this truck, has pretty much come from LC and LS, the rest has been created specifically for this truck. Toyota has been very clear on their stance for electrification rather than throwing all the eggs in the EV basket where it doesn't make sense (like a tow truck).
I would also guess that the top engineers are working on battery technology since Toyota has committed to spending crazy amounts of money to develop that tech, I hope you understand that batteries are used in hybrids as well as Ev. Literally the same batteries except larger. So Increased battery capacity, benefits both kinds of vehicles.