As with anything, it depends on how stable the existing floor is. There's certainly no technical reason that I can think of to rule it out.
It's like re-plastering/re-painting/papering etc, the existing must be already firm and well fixed. I know some floors need a roll of thin "bedding" material down first, but otherwise, carry on.
I'm assuming the new floor is to be glued down?
Seems OK on the face of it, although as laminates are frequently laid on a thin soft lining so they give very slightly I wonder whether you would get creaking between the two surfaces (wood/laminate) if you put wood on top.
If the original 'sub-floor' is sound then there is no reason to have any fear of overlaying the existing laminate with wood. However, whilst woofgang might appear to being humorous about lowering the height of the room, he has made a very valid and serious point for consideration about having to adjust the bottoms of doors and thresholds.