Haha yep, I’ve definitely seen that happen. I’m day to day dealing with music, so whenever something does go live too early or get leaked it’s a real shame for the artist and team who have planned every last bit of the launch.
I think in this case the pages I’ve found were set live with the staff members thinking people just wouldn’t find them ahead of launch and without direct links from the app. It’s an easy mistake to make, but as I say I don’t want to ruin it for the team by saying too much more.