Yes, in Maryland. Every state is different (i'd imagine not every state even has "specialty" plates), I don't know what's more common.

But I imagined the whole reason they have "specialty" plates is revenue generation?

https://mva.maryland.gov/about-mva/Pages/info/27300/27300-29...

I think "specialty" plates are silly. I am old enough to remember when there was one option, and for every state it was white letters on a different solid color background, and that was fine.