Let me explain.
Bear in mind this was explained to me, i am not a primary source, though my experience does correlate.
All the different types of chlorophyll are present in the plant. BUT, the plant will tailor which are most concetrated based on what light is falling on it. I.e, if there is no 460nm blue light, the chrlophyll that is adapted for that wavelength will be lying dormant in the plant while it cranks up the activity of the chlorophyll that are being used most.
CFLs have a nice smooth spectral distribution, so chances are that a wide range of chlorophyll are active. If you were to then switch to LED that is only putting out a few narrow bands of light, the plant's chlorophyll will have to adapt to take maximum advantage of the new spectra it is recieving lots of, while the others become dormant.
My theory is that you would be forcing the plant to reconfigure its photosynthesis, thereby losing energy/time.
So to answer your question - No, i dont think it would
shock them, BUT if you were vegging with the LED spectra, your plants would already be adapted for those wavelengths and thus would be more "at home" when you put them in to flower: meaning they are better adapted to get the most out of your LEDs.
I say again that i have no experimental backing for this or any real knowledge of plant biology. This is based on my own experience, reading on here, and a conversation over a spliff with a plant biologist who explained chlorophyll to me