Wouldn't make any sense to me because theres no point in designing an old antique engine to put in a new production truck. Only reason I see in toyota designing a pushrod engine was for the Nascar series. They were using ford engines initially because Toyota didn't have any pushrod engines at the time. I saw something on speed about toyota going to TRD to design the new engine for their race car. I don't see why those rednecks don't allow new engines to enter, maybe cause they bitch and cry about getting spanked and thats why they never want to upgrade. Now whether or not they borrowed the design from Ford I don't know because I really don't care. Now as far as the new Tundra having an old pushrod engine. I dont think so according to the Toyota website. It also wouldn't make sense considering they already have a great design.

All the 3 options for engines are DOHC.
Toyota.com : Vehicles : Tundra : Specifications