I would like to see the Dragonfly tested because I think this is major conjecture by Mekhissi. To trot out the PBs of Cheptegei is silly because as LRC has pointed out, his PBs/credentials were quite similar to Bekele's before Bekele knocked out his records with major breakthroughs. The women's 5000 record was soft, and Gidey's 15K performance and absurd junior career were of note. Also, does he really think this is a "Nike Dragonfly" thing exclusively when we've seen unbelievable times from Elly Purrier (New Balance), Nicholas Kimeli (Adidas~ 12:51 going out at 12:35 pace), and Shelby Houlihan (Nike Victory). Not to mention Rhonex Kipruto on the roads (Adidas).
Of course, Bekele was a generational runner, but is the absurd appearance of this 10,000m time in relation to KB's times more connected to a drought in the next generational talent combined with the would-be best contender (Farah) refusing to time trial as top-level 10,000s disappeared? In a non-championship year, it was ripe for some athletes to run reallly fast, and I think technology and the spike is just a small part of the equation here.