While I am not a WebAssist employee, I think I can answer the question for you.
The PowerCMS solution was created long before the new HTMLEditor was released. With that said, WebAssist did a dot release update just to include the latest version of HTMLEditor but the solution still kept the same functionality - just with newer software.
The next release of PowerCMS, however, will include new features and likely the advanced file management system already in place (most likely something that will get activated through a wizard upon setup). Not sure if you have seen some of the newer WebAssist solutions like PowerStore 3 or the PowerGallery, but they have great intuitive setups making it far easier now. My guess is that they are completing a new version of PowerCMS that will also follow this model and bring in some really robust features.
I am actually working on a new tutorial to activate the Advanced File Manager in PowerCMS as I have done this on a couple of sites already. I will post to let you know when the tutorial is ready.