According to our Product Manager, CNC Tech rectangular header connector 3221-10-0300-00-TR does not have a shelf life. I would assume this would apply for all similar connectors within the same manufacturer series.
See also:
HIROSE DF3A-xP-2DS Connector Shelf Life
Shelf life of TE 825433 Header Male Pin
Shelf life of Molex’s SlimStack Board-to-Board Connectors