The change in % from 50 to 40 for CoC rec had been discussed for about two years. The thought process behind it was they wanted less subjective weight, such as ranking and more concrete weight, such as AFOQT, cgpa and PFT. The talk of the change came around the same time PCSM2.0 was being implemented.
JMPO, I doubt they are going to increase class size for each Max because they did this two or three years ago,. They went from six Max classes to five, but sent the same number of cadets. They only did this for one year and decided for whatever reasons that it was not a path they wanted to continue with for SFT.
The numbers that people are postiing for their dets are quite large, thus unfortunately it would appear that the 90%+ from the past few years would not be possible for this year. Remember the AF is still trying to decrease ADAF by 8% over the next five years. I think our DS's class was the last year group that had the 55% rate and used the AFOQT for selection. His det is considered large, and they only commissioned 26 officers in the end. The det had over 250 cadets between the 100-500s. The average retention rate for their unit was the same as the nation which was about 25%. It has only been for the last few years that the rate had increased to a higher level.
As for telling the cadet if their packages were sent I would bet they did, however, that doesn't mean that the CoC held what in the ADAF world is called a mini-board. IOWS, the CoC decided at their level to determine which cadets they thought were not in the running and decided not to submit their names. In our DSs year group his CoC did not do a mini-board, they sent every name up to HQ and let them decide the cadets that would attend. Thus, unless you know if a min board was held than it really means nothing. Plus, even if a min board was held, depending on the numbers they have allotted for SFT it doesn't mean anything either way. The only way a cadet should feel safe for selection is if they are in the top 1/3, carrying at least a 3.1+ (tech, 3.4+ non-tech). PFA of 97+, and an AFOQT that is at least in the high 80s.
~ Note there will be cadets with lower stats, just saying from a breathing perspective, that is something I would say from a chance me position you should feel pretty confident. It is when you start slipping in any one of these categories that the safe position is weakened.