Yes. Even where I am in NJ right now added hookups at some sites maybe 3 years ago. When I look online, they are often booked, at least on the weekends and during the week during beach season. (The closest shore town is only about 11 miles away. I rode there today.) The nice thing is that those sites are in their own area away from most of the other sites.

Caoe Henlopen, which I mentioned above, also added hookups maybe 6 years ago. They are also away from tents sites, and generators are still not allowed in anywhere in the park.

I did a tour in VT in 2020. I stayed almost exclusively in state parks. I don’t remember seeing hookups. One interesting thing is that at at least some of the parks they had small cottages/dwellings where an employee lived. Guess it’s a good way to attract workers when there are no population centers close.