Well I think ZC would be canon... or at least in some ways for the campaign
Well, the idea may not be as weird if the legacy of ZC is the indirect link of a future Sith Lord, passed down from an ancient sith lord...
While it may be a bit too far fatched, but there is the slim chance that things are all connected.
kotor3 => ?? => FoC => ?? => Darth Krayt
So far the timeline is still right.
If anything this would open up more things to be played with in the future "Dark Times" era tv series.