I'm not saying authorial intent isn't important, it's when that authorial intent goes against major continuity that it should be discounted. This has nothing to do with "canon" or "headcanon" or "personal canon" or anything of that ilk. I, personally, dont have a personal canon. This has to do with valid sources which are used to write other articles. I don't think that you could say in good faith that a separate coninuity in which the Ninth Doctor (no, not the Ninth Doctor) travels with an android Master that is completely ignored by all other media and described as "unnoficial" by the DVD contents itself is of a standard to refer to entirely plainly on pages of stories such as Utopia, Domain of the Voord or even Horror of Glam Rock.
Likewise, a story in which The Doctor dies unambiguously with no hint of resolution from the either the BBC or production team that is also, quite unashamedly, a middle finger to all successive stories in the franchise should not be referred to in articles such as Journey's End.
Stories like these muddle the wiki for our standard user, who might just be coming here to look at Nardole or something, and so they should not be used to write articles for stories in which continuity is entirely different.