Given that the behavior of "distraction free mode" is nothing more than full screen mode, as it is called by basically every other KDE application that has it, the feature should be called 'full screen mode' for consistency. Right now the user thinks that it offers something special, as "Presentation mode" does in Okular. It is also assigned the same default shortcut, ctrl + F, that is used for full screen mode in other applications.
By the way, the fact that "distraction free" has become fashionable jargon in the word processing world is poor grounds for relabeling the feature which already has a *better* and more appropriate (though less fashionable) label right now.
See: https://phabricator.kde.org/D18448
Cheers!