I think forced induction on future Lexus F models is maybe less probable than we would want/expect. I think the non-F's will have turbo chargers because they are inexpensive in terms of what is gained, and is the most logical evolution of Lexus' engine line-up. But the future of performance is honestly in the electric motors and all wheel drive. Especially for the Japanese automakers who must make vehicles to the Japanese governments standards/expectations.
The NSX has the electric motors, the next-gen GT-R will likely be a hybrid set-up, and Mitsubishi is rather bonkers with their affinity for hybrid drivetrains. Please also remember than Toyota has a Le Mans Prototype. A V8+electric motors on the LC F makes the most sense under Yaguchi, as he can still retain a visceral NA V8, hooked up to the two electric motors. Paired with a Toyota twin-clutch transmission that has been being developed since before the LFA (it was suppose to go into the LFA).
All wheel drive is probably the future of most high performance cars, because putting the power to the ground is not so easy once you are above ~550HP and your car is made out of carbon fiber. [Unless your car is just heavy, a la that fatty, the RC F or SRT Hellcats.] So no, I do not expect to see forced induction in future F models, but definitely on non-F's. I don't know when to even expect an LC to be released, but I imagine not anytime soon, so that would mean even more time would have passed, and more likely to receive the electric motors.
I feel the LC will be the more attainable LFA, so I think it will have some sort of groundbreaking changes for Lexus. [i.e. dual-clutch, different powertrain, more carbon fiber.] I think it was Yaguchi who said when they design the F cars, they do not try to develop the cars to be analogs of ///M's or AMG's, and those cars have the Twin Turbos. And for those of you that still don't understand F Marque... F Marque is rather different, they just does what they want, not really caring about comparisons.
It's probably safe to say, if you want twin turbos, go get an M or AMG car. There's probably some reason that TMG TT V8 was never pushed as a performance motor in an F.