It was discussed. It's pretty much what you feel is happening, just more intense simulated engine braking.... achieved with more regenerative braking.

As Tim mentioned, the shifter (like the accelerator and brake pedals) is a purely electronic control. There are no mechanical linkages to it so a shift between D and L is just sending different requests through the vehicle's control module. The same thing as using L can be achieved with light pressure on the brake pedal (sending the same basic instructions via a different combo of inputs).

So, it's no problem, nothing to wear out if you use L. My engineer on my drive-along said "Oh, you use that trick too? I like to shift to L to slow down as well."