That's where it becomes tricky. What IS canon anyway? We all have differeing opinions on what constitutes canon and we all feel we're right. That is where fic labels can get tricky and messy.

As far as I'm concernd, Jack/Sam isn't canon. I see what TPTB are doing. I know what their intent is. But the most I've ever seen is some canon AU pairings and some UST between the characters in the reality we watch. Since neither seems overly invested in stepping out of their "safe" area, the most I can say is they have some canon UST, but they aren't a canon pairing.