https://alphatheta.com/en/information/dj-brands-unite-to-launch-onelibrary/
    
Looks like device library plus (CDJ 3000X, Opus Quad etc.) will be renamed to OneLibrary and Djay and Traktor will be granted to implement import/export to it.
That means you will at some point in the future plug in a Rekordbox USB, see the playlists and tracks in Djay and Traktor, changed it grid, add new tracks, create new playlists. Take that same USB, plug it into the CDJ-3000X at the club and play 'dem tunes.
Will not work on CDJ-3000 non X and older I guess.
Knowing Native Instruments they have an implementation ready in no time, if your definition of no time is 2 years.