It would have to predict the model numbers of the planes though: some newer ones I have been to (A350s) seem to have automagic dimming windows. Getting on flights with such windows is better even if you have to sit in the sun!
Boeings 787 also have this. There isn't even a lid to close/open the window. And in some situations you can't "undim" it. Kind of annoying when it's midnight and you want to take a look at the moon and stars.
I hate those windows, when fully dimmed they let through a lot of blue light, and blue light is bad for sleep.
On the other hand though I detest window seat passengers who insist on having the windows closed for take-off and landing. I'd like to know when to expect a thud, thanks. The electric shades are nice in that aspect because they are never fully opaque.
I don't know, it would make sense for the US FAA to require that but I don't have the authority to ask that of the window seat passenger, and most flight attendants don't care.
They're more concerned that my seat back is not pushed back by the 3mm that they move.