Last time I checked they do, maybe not as fast but they will eventually. Ge says poly refactors only have a 30 000 hour life! Acrylic is around 100 000 hours and glass is forever.
They won't yellow as bad or as fast as polycarbonate. As long as it's used in a proper wattage range it will do fine. There's acrylic lenses on M-250Rs from the 70's on my grandparents' street and none of them have the slightest bit of yellowing to them except for one polycarbonate one that is as brown as a bar of chocolate. I think the light is a dayburner too, but I can't tell through the lens.