You're looking at this incorrectly.

High value awards subject to capacity controls are not increasing but the airlines are flooding the markets with miles via selling them to the partners (Chase for CO, AMEX for DL, etc.).

Thus there are not only more miles chasing a finite amount of standard awards, and those that were previously out of reach due to high amounts (QF F @ 135,000) are now in reach. This coupled with increasing LF's throughout the industry will pressure the airlines to 'give' away even fewer seats as they can be sold instead.

As peoples' balances are presumably increasing due to partner distributions, the high mileage thresholds that once served as a roadblock is becoming less effective. For QF I don't think this is really an issue as there was no way to redeem a capacity free reward with them from OP miles but for capacity free rewards we see either the rates increasing (as what's happening on CO) or certain flights becoming ineligible for capacity free redemption (as what's happening on DL).

The airlines must be cautious to match reward inventory expense to revenue received from partner mileage sales or else people will no longer pay a premium to the partners for the ability to accrue miles...and then in turn the airlines will watch their profits on mileage sales erode.

One hopes they have the foresight not to kill the goose laying the golden eggs.