No. I had Glance always on when charging on my 920 for 3 years. It never caused any screen burn. Granted that was an IPS screen vs. amoled in the 950XL. Also I believe that the glance screen alternates pixels so that burn in does not occur.
so long as the screen refreshes and moves the text - even slightly - it will be fine.
The 808 moved it around the screen, not just a few pixels, but all over the screen... i still use it for my camera.
The N9 does the same...