Quick question on CX class availability
 

After days of showing barely J and Y availability all of a sudden, for a whole day today, my flight is showing this:

Cabin class: F2 A2 J8 C8 D7 I5 Y9 B9 H9 K9 M7 L5 V4 S4 N0 Q0 O0

Did a few tour groups just canceled their trips or what would cause this massive turn around in availability?

It's called yield management. They try and force as many people as possible into paying full fare Y (or close to it) by pretending they've sold out the lower classes, then when then think they've captured all the people who will book for that flight even at full fare they open up the lower fare buckets to get the people who are more price sensitive. It's the fairly obvious way of maximising the revenue for the flight if you get the timing right.

And, expanding on what Christep said, they do the same with awards and discounted premium seats. A few years ago, before the great travel slump, they hardly allocated any seats at all to the A bucket on 830, 831, 840 and 841. Thus it was impossible to get these flights on an AONEx ticket. Now, however, they're plentiful.

Also, if you watch for F awards, you'll see that availability comes and goes as they try to manage revenue pax versus awards.