Is this just an SEO score with a different name?

No, and the difference is the point. An SEO score implies completeness: that the tool looked at everything that matters and produced a verdict. This did not. It fetched one page, once, from outside, and reported what it could see.

A thermometer is a genuinely limited instrument, and nobody resents it for not being an MRI. Calling this a score would be claiming an authority it does not have.