Not sure if this will add to the discussion but:
"Personally I define canon as "that which is in the sets and in the published storyline from LEGO." Others have a more... liberal and selective approach. Whatever works for everyone. I've had endless grief over trying to say something is canon but people don't agree. So I find it best to let everyone decide for themselves." - Binkmeister
I asked him about how he defined canon because I was confused, and still am, on what he thinks about canonicity.