en.wikipedia.org/wiki/Methuselah

Aubrey de Grey published a paper titled "The singularity and the Methuselarity: similarities and differences" in 2009, which shows the term was in documented use before 2010. In the paper's abstract, de Grey writes that he "here christen[s] the 'Methuselarity'", directly contradicting the article's claim that the word was coined in 2010.

There is also independent 2009 evidence from a transcript of de Grey's H+ Summit talk. In that talk, he says the concept was "given its name a couple of years ago" and "not by me", attributing the name to a friend. That means the article is wrong at least on the year, and possibly also on who coined it.

So the safe correction is: the term was already in use by 2009, not first coined in 2010.

The sentence attributes a specific priesthood succession story to the Book of Enoch (normally meaning 1 Enoch), but the evidence places that episode in 2 Enoch / Slavonic Enoch instead.

A standard summary of The Book of Enoch describes its contents as the fall of the angels, Enoch's heavenly journeys, and apocalyptic visions. In that summary, the section involving Methuselah concerns Enoch's revelations, Noah, the Flood, and cosmic visions—not a scene where Methuselah is made priest and Nir is appointed his successor.

By contrast, textual and scholarly sources on 2 Enoch explicitly place the priestly succession there. A Marquette-hosted text of 2 Enoch includes Noah speaking to his brother Nir, and scholarly discussion of the Melchizedek section states that Methuselah invested Nir in priestly garb. That is the episode this Wikipedia sentence is describing.

So the problem is not that the tradition does not exist; it is that the article assigns it to the wrong book. The priestly succession of Methuselah → Nir is a feature of 2 Enoch / Slavonic Enoch, not the Book of Enoch (1 Enoch).