Thread:Acidwyre/@comment-1672596-20141201022850

Look, I'm not particularly fond of Return to the Sea myself (even though I view it to be much better than Ariel's Beginning), and personally wish it weren't canon (even though I have little problem with Melody herself), but the problem is, Return to the Sea was considered canon by Disney since they not only rereleased the game, they even gave it a special edition and was included in boxed sets. I can name plenty of non-canonical works that DON'T get any rereleases at all, much less be included in boxed sets or given special editions. For starters, Metal Gear: Ghost Babel, known outside Japan as Metal Gear Solid (not to be confused with the actual Metal Gear Solid for the PlayStation), was a non-canonical entry made for the European market. It has not gotten a rerelease at all despite overwhelmingly positive reviews, not even a Virtual Console/PSN/XBL rerelease. Same with Snake's Revenge and even the NES version of Metal Gear (the latter of which Kojima explicitly disowned. The closest it got to a rerelease is as a bonus package for The Twin Snakes in the Japanese release, and that isn't really a rerelease so much as a bonus.). Oh, and The Twin Snakes to some extent (which is at best semi-canon due to MGS4 using its audio at certain points, especially Act 4, even if it's mostly because the original's audio in the English released was unable to be salvaged due to certain precautions not being met like using a soundproof voice acting booth). Also, the Ac!d games don't get any rereleases either AFAIK. Even Portable Ops, which is basically treated as canon yet mostly ignored and not included in collections starting with peace walker, got rereleases via the PSN and also combo packs. And even the MSX2 games which thanks to various retcons are barely even canon got rereleases, not just in the official collections (namely via Subsistence), but also digital downloads (more specifically the Wii Virtual Console in Japan).

And considering it got rereleases despite John Lasseter, who was very vocal about his hate for the DTV sequels and basically canceled production of them, running WDAS now (and believe me, considering how he hated them and is running the group that makes animated films for a living, he most certainly could cancel and destroy any and all copies if he so desired), that's another reason why they are canon. 