Correct me if I am wrong but if I remember correctly you could star/mark any place on Google maps before. Have the update on my Android now and also the web version and it seems I only can star an actual addresses.
We will be camping soon and the camping ground is in the middle of nowhere. Wanted to star it just to have it on my map. Unfortunately I didn't find any way to do that. If that was possible before ... and I am pretty sure it was ... then I hope Google will bring this back or if it is just well hidden make it more obvious again.
Seems I am on a roll. Another post today.
I wish you well