Why No Warning?🥲🥲

There is a warning in this support document (it took me some time to find it): Set up Family Sharing - Apple Support

But the document is saying something different from what you have seen:

"Remember, you can only join one family at a time, and you can only switch to a different family group once per year."

You are write - it would help to receive a warning, when you are about to disable family sharing or are trying to change your family sharing status.