evmori,
I don't understand where you're coming from.
If "parent or guardian" can be interpreted to refer to a temporary guardian, then a non-relative Scoutmaster or ASM could tent with a Scout. That's clearly not the intent and purpose of the G2SS and YP rules.
"Parent or guardian" has a very clear meaning in general usage. If you use a very loose interpretation of "guardian," then it seems that any temporary guardian could sign permission slips, medical forms, etc. That's clearly not how things work.
Lots of contradiction in the wording throughout the G2SS and even on the permission form.
Unless you are the author of the document, I doubt if you know what the intent and purpose of the document is.
"Parent or guardian" Do you see the word legal? I don't. And as I stated, this is inconsistent throughout the G2SS. This should be corrected by National then there is no question.