It's interesting, a couple of months ago I was looking at a KIX-TPE redemption for early January next year and like the op, I thought that CI had plenty of seats available in both business and economy across all 3 daily flights.
If you wanted a specific flight it may not have been available but it was easy to redeem a flight as long as you were flexible. For example, I wanted CI157 but had to settle for another flight as there were no business class seats left on CI157 that day. There were also plenty of economy seats available at the time on most flights.
So the inventory had definitely been loaded for the KIX-TPE direction at least, but when I checked again the next day after I booked the flight, all the remaining inventory around early January had just disappeared.
It's highly unlikely that every remaining seat would have been taken up in such a short time as there were so many seats available, so I'm guessing it must have been pulled for whatever reason.