Nope. It has always been Sanskrit.

This last guy claimed that those languages also derived from it.

And he didn't like "those people" either.

There might have been aliens into the mix as well.

Can't be Tamil, that's a Dravidian language - not Indo-European. It's usually Sanskrit because that's the High Language.

Tamils also have a similar concept.

Tamils mostly take pride in the age of their language and its continued use till date. They also make their identity around this. They don't claim that every language originated from theirs or that computers need to be programmed with Tamil.

A lot of them absolutely do. there are plenty of memes about You lot doing the same thing. Just search for "Tamil language original meme"