It is not like most TVs. TVs have both a start and finish key frame.
This only has the start frame, and just guesses at what the finish frame is going to be.
This is very differant.
Actually they are using at least 2 preceding frames, because they need more than one to predict the direction of the future frame.
So they are both using at least 2 frames to interpolate/extrapolate another.
It's very similar. Though doing in between frames helps with the accuracy because you know the end state, but at the cost of additional lag.
Predicting a future frame from two past frames is harder, but should have much more limited impact on lag. But the important point, no matter how good it is your lag will still be at the real base frame rate, not the new fabricated one.
Even if it introduced Zero Lag (unlikely), and had no obvious artifacts (unlikely) it would still not improve reactivity like a real frame rate increase would.
If your game is running at 30 FPS, and you extrapolate it to 60 FPS, it would less responsive than if you just turned down some settings and ran a real 45 FPS.