Its not on some timelines and it is shown on other timelines... The timelines of this series are always in a flux its ridiculous. A new one gets printed almost every other year. The timelines are all inconsistent.
Half the time when people discuss this subject, I notice they put in alot of hyperbole and personal interpretations, misquotes, and misrepresentations of quotes without citing proper evidence.
As Jorge pointed out mistranslations of interviews adds to the problem as well.
So I wouldn't consider your word more reliable than another... All I see is different people with different interpretations of what is and isn't canon... based on their interpretations of rough translations in interviews, that may not necessarily mean what people interpret them to mean. ...or people misremebering what they think they read...
Actually most of the time from what I've seen the term canon is never even used in any interviews...
Also, the term "timeline" in and of its self is a vague term. I.E. If I was talking about the timeline of history of Madagascar in 1920s, I probably wouldn't be inserting events from the history of Nebraska in the 1920s. As that datapoint would be irrelevent to the Madagascar's history. Yet both have history that occured in the 1920s. Just one is irrelevent to the other.
In other words not being listed on a timeline in and of itself doesn't "deny" canoncity.
I don't always know what IGA is trying to convey, the translations of his words can sometimes be contradictory. I think its pretty clear that IGA intentionally removed Legends from the story. But his comments for the N64 games were not removed, they were always "side projects"
http://www.1up.com/do/feature?pager.offset=4&cId=3152109. have been how can I put this "open to interpretation" by the fans... It may be possible that "side project" just means that it occurs in the same history, but is not relevent to a particular timeline IGA was trying to tell. The debates will probably never end...
Also, IGA once admited that story is not exactly his reason for making the games... He doesn't make the games to tell the story... He makes a story after he's designed the game's interface, and decides what kind of story will fit.