So let me try to understand.
OP made an extraordinary claim without extraordinary evidence regarding stolen content, and decided to back out of it as soon as people pressed further to get answers, so nothing outside of coincidental resemblance is all we get?
If truly Nintendo was picking up from content uploaded online by a 3rd party and we had solid evidence to prove it I would believe it, but for now we only got a single example, and by the look of it, an overreacting response to it.
I would be genuinely curious if more of such examples could be identified, just for the sake of it.
It would be easy enough to get perfectly matching data if the ripped soundtracks available online were already very accurate to the source material.