Johnny; yes, in this context, it means "has been set". You cannot check something that
will be set! Regarding your first question:
a check shall be made
Everywhere I have worked defines
how the check shall be made, so there is no ambiguity. eg. "the aircraft is squawking the assigned code (code/callsign correlation) at the correct altitude in an expected position" or words to that effect. Some places say that code/callsign correlation is
nota sufficient check.