XVR,
As I stated on PPrune you do have to be 40 and served 20 years to qualify for EDP under afps15. Under afps 05 it was 40 years old and 18 years served which meant under 18's who served only 22 wouldn't have got an EDP so this new 20/40 engagement is a winner for them if it allows them to serve to aged 40.
The main unanswered question (and where the DIN was wooly in it's interpretation of afps edp) is does the new 20/40 engagement guarantee meeting the afps15 EDP conditions I.e. no matter how old you are when you join up if promoted to cpl you can expect an offer of service to either your 20 year point if you joined aged over 20 or to 21,22,23 or 24 year point if you joined up younger.
If you are currently on for 22 then you will not be forced to serve less, however what happens if you are aged under 40 at that point is not clear wrt the afps15 part of your pension is concerned (the afps 75 will NOT be affected) continuance to reach aged 40 would seem appropriate.
Whilst the 20/40 is for new entrants post 2015 it also says you will take it if you accept a change to your current engagement I.e. SAC who joins pre 2015 but is promoted after 2015 will go onto 20/40 not 22 years.
XVR, you need to put your detailsninto the new updated pension calculator, I put a 17 year old joining up and serving 22 years leaving aged 39, put them as joining in 2003, they only got resettlement grant of £10k and preserved pension at 65 according to the calculator.