every detail? of course not. The option "save in password manager" is dramatically underdocumented to the point of seeming breakage. When it comes to --symmetric this manual just has nothing to say itself.
utterly false advertisement! You're better off using gpg than Kgpg in many cases.
every detail - LOL.
There are huge gaping holes in the documentation, e.g. the complete list of keyrings and how their passwords are set is missing. Without these crucial elements this wiki entry is pretty much a joke.
I'm sure the handbook was complete when this "false advertisment" was written. KPkg has moved on in the intervening 10 years. It is unfortunate that the manual has not moved along in the same pace. Sadly, documentation is an area, that doesn't attract enough contributors.
If you care about the handbooks for KGpg (or any other KDE software for that matter) the best thing to do is to start contributing. You can get in touch with the documentation team on IRC og via their mailing list.