It's good airmanship in the scenario you describe to call up the MATZ and tell them where you are.
They may give you a squawk and a Basic or even a Traffic service if they're busy:
In my neck of the woods I always speak to the cousins as their CMATZ gets busy with all manner of tin during the week.
Even though the CMATZ recently reduced in size, operating as I do from very close to the MATZ I wouldn't dream of not speakng to them.
The attitude 'I don't have to speak to the MATZ if I'm near or passing through, so I won't' is unhelpful and potentially dangerous.
Cusco.