"Class award availability" refers to the availability of seats or tickets in a specific class (such as economy, business, or first class) for booking through rewards programs or with points instead of paying with money. Full definition
I did a quick search for Business Class award availability found quite a lot of dates with 2 award seats open for the new route.... (travelingformiles.com)
With its generous first class award availability, they really shine when it comes to access for families. (upgradedpoints.com)
At the time, there was a single date in all of 2014 with first or business class award availability at the saver level. (onemileatatime.boardingarea.com)