Thanks for flagging this, and I can see what you mean. All interfaces used by a snap need to be added to a snap’s snapcraft.yaml, regardless of whether they’ll be connected automatically to the system after they’ve been installed by the user. Then:
This is from the text above the table. But I can see that this isn’t 100% clear - it’s also possible for a snap developer to request permission for their snap to auto-connect an interface that wouldn’t ordinarily auto-connect. I’ll update the text at the top to explain this.