I know the real answer is, "Don't take this stuff so seriously, don't worry about whether or not something is canon! Just enjoy the story or not!" but I can't help wanting to dissect this! Why do this at all? Why not just leave Freemaker Adventures as firmly not canon? I want to know that, too!

I don't think Netflix will be able to add Adventure Time to its lineup, because last I checked Hulu has the rights for it, which is too bad, because I think it would fit in well with their line-up! But there are probably other places online that a Google search would turn up. XD