Maybe there is no reason for a change now when everybody has gotten used to them. But there was no real recent for a change in the first place
I believe it was to add the three command ranks (CC and etc) and Prob. PC. As they removed cso, SPC, DSGT and DI.
@Jason Detiri No. It was done because of realism. DI, SPC, DSGT etc aren't existing ranks in real life.
SPC is technically a police rank, Special Police Constables are volentry workers for the police.. alas I can see what you are getting at.
DIs are a real rank, I would like to see DC, DS (Detective Seargent), DI, DCI, DSI and DCSI, will be fun having a different route to go down! ( @CC Joseph Tadworth )