Subaru does not translate to "seven sisters" (or even six sisters) so bringing up Subaru would undermine the claim of the article
[0]https://web.archive.org/web/20100411083646/http://www.subaru...
I don’t see anyone claiming that Subaru means seven sisters. It’s just another name for the same constellation.
[1]: https://web.archive.org/web/20100411083646/http://www.subaru...
Unfortunately, trying to find anything more online, such as what exactly the Kojiki says about them, doesn't seem to yield much.
So it is very similar to the lost Pleiad, but the seventh fairy is taken back by her god father.
So even if we're being very literal, "the one with the two stars at the same time" is an accurate description of both the hidden sister story and the cluster.