I'm not personally aware of any laws against illuminated reticles, but I don't know the laws for every state, and I'm sure they're all worded differently. Lots of states have explicit laws against infrared, night vision, lasers, or any other devices that improve your ability to see in darkness.

Illuminated reticles don't project any light outside the device, nor do they improve your ability to see in the dark. So I question whether or not illuminated reticles were ever meant to be prohibited by state law in the first place. More likely they're just assumed to be by some enforcement officials, and this has been spread by hunters over the years as illuminated reticles have become more prevalent.

I think most of the issues with legality are more focused on what you're hunting in low light/at night, and whether or not the hunt is actually legal. You don't want to be caught by a game warden in the PA deer season late at night with an illuminated reticle. Not because of the legality of the reticle, but because of the appearance of poaching and the fact that game wardens can be a little overzealous.

I like illuminated scopes for their ability to extend the hunt from the earliest to the latest legal time without having to worry about spotting my reticle. But for night time varmint hunting, I currently use a red flashlight attachment.