Some within continuity, it says, not canon- small difference. EU stories like, say, The Approaching Storm make an effort to stay within continuity, even though they are not canon. Whereas ones dealing with Boba Fett's past, or Splinter of the Mind's Eye, or the Infinities series... are very much NOT in continuity, some deliberately so.
And as that story is in the EU section, it most likely refers to EU continuity anyway. So the point is that some of these stories- including the Maul one- are making no effort at all to fit in with any form of established continuity at all!
In any case, clearly not Episode III related, so moving...