Well, I can maybe maybe see where these crazy fans are coming from.
For example, the recent revival of Fiddler. Sure, you can cast someone like Alfred Molina in the role of Tevye, and while I don't know what his childhood, or religious beliefs are like, I don't believe he is, or ever was Jewish. This greatly effected his performance, and the whole show quite negatively, as it became a sanitized version of the show. What made Zero Mostel so iconic was the knowledge, and experience of being Jewish, as well as understanding and living with those people who most likely had immigrated into the US. This is also what made Harvey's performance so much better, despite that a voice and a personality that doesn't exactly scream tevye on the surface.
That being said, that should not prevent anyone of any religion, race or nationality in this case, from performing certain music, or songs. Them not being Hispanic or Latino doesn't give them that inherent advantage of knowing what it's like to be one when performing that someone who is Hispanic or Latino would automatically have.
It's like when a person sings a song about losing someone who they love, or has died. Many people who sing these songs might not actually go through these experiences, menaing they don't quite know the real feeling of it because they haven't gone through it, but by no means does that mean they shouldn't be allowed to perform these songs.
In other words, those people who posted the videos have every right to sing those songs....even if it makes no sense, or they don't quite do it right.
-There's the muddle in the middle. There's the puddle where the poodle did the piddle."