Imo a logical interpretation of "shadow ban" would be when you are banned but they didn't tell you they banned you, and regular "ban" is when they tell you you were banned. It makes enough sense that people don't think they need to look it up to confirm.

edit: funny enough, I did double-check the wikipedia page to make sure my understanding was correct, but upon reading further it does acknowledge the expanding of the definition: https://en.wikipedia.org/wiki/Shadow_banning