OK, I presume you downloaded the current student handbook which was produced in September of 2019. That's the version of the student handbook linked to by the article, and as far as I can tell the latest version from the school district.
The meeting where the school board voted to add a new "secure storage" notification happened "last week" or more particularly on February 6th, 2020.
So how is reading the old student handbook from 2019 relevant to the content that the school board voted to add in February 2020?
Did you even read the posted article?
After all the hyper-ventilation on this thread, yes I did read it all.
Relevant is that according to Arizona law (refernced in the handbook), the board must get the parents permission to ask about any thing gun related. So, again, I dont see any down side to providing parent (who may be ignorant themselves) as to how to properly secure guns from unauthorized persons or minors. There is no legal obligation to sign anything here. The law trumps whatever the school board may send out.