"...DO NOT POP A SLIDE..."
I am sure the company was referring to non emergency situations
When the airplane is on the ground in a non-emergency situation, at the gate the slides are not locked to the plane- understand? This way, the slides won’t be activated to inflate into the plane if the door is closed and then reopened.
When the plane is detached from the gateway, the flight attendants will attach the slides to the plane which also attaches a pull that will pop the slide if the door is opened in an emergency situation.
You will hear flight attendants acknowledge ‘cross check’ or ‘cross check complete’ as they check behind each other to make sure they are attached or unattached, depending on where the plane is.
To sum it up, you don’t know what you are talking about.