The symbol is the first image on google when you search for swastika Star of David (or it was, now Ye images are showing up lol), and given the context of his por-hitler and pro-nazi rant, I think it's far more likely than not Ye had no idea the UFO connection.

Which makes it really weird in context, because the Raelians are using it in its original non-violent sense, but Kanye West is explicitly pushing anti-semitic messaging. Which leads me to assume Kanye either thought he was being clever or just doesn't understand the intended context of the symbol he posted.