When we wrote this, I at least had it in my head that detectives are generally not strictly uniformed, and therefore not covered under Uniformed security employees. CSIs I believe do have some sort of uniform jacket or outfit. Since command is the group that enforces this expectation however, the interpretation of both of those instances is best left to them.
In regards to the OP: I was neither the original submitter of this idea nor in the (rather strong) majority of people in CCIA channels who recommended we add it to Uniform Policy. Because support for it there was very strong however, we decided to try it out.
The main driver of the change was @The lancer who I would like to have post here with a summary of what he hopes the changes will drive.
I think I've explained this to Paradox before as well, but just in case there is any confusion, AFAIK this policy has nothing to do with the Cloak PR or dev's denial of it. It was unfortunate timing that both issues arose at the same time, separately.