LED vs. CRT
Yes, LED's wash out (turn black opaque) when turned sideways. Cell phones, hand held GPS's, et al. have LED displays. CRT's (cathode ray tubes) as found in glass cockpits do not have this feature. As far as some CRT's having polarized glass shields, I don't know. As far as the E-120 and CRJ, I have had no problem reading the screens. As stated before the heated windshields sometimes show lines of polarization. This is dependent on the temperature of the windshield surface and the angle of the sunlight passing through the glass. Usually not a problem. Most (if not all) glass cockpits have CRT's and not LED's.
Unless you answer your cell phone sideways or look at you Garmin sideways, you should not have a problem.