For colleges currently providing live course information, 'Seats Left' refers to how many spots are remaining in the class. How current that number is can be determined by the associated timestamp.
'Seat count unavailable' is not an indicator of whether or not a course is still open, it simply means the college is not providing a live update of seat counts to CVC.edu at this time. Current seat count and open/waitlisted status information can be found on the college's website, typically in the online searchable class schedule.
CVC is working hard to to implement live course information across the entire California Community College system.