Also, wtf is "narratives are hard"? It sounds like typical condescending Twitter-speak, but I have no fucking idea what it means in this context.
I think he's saying that, despite their zeitgeist prominence, certain narratives are difficult to legitimize by criteria not rooted in confirmation bias.
So in this case, the initial narrative was that the ACC is a "weak" conference.(e.g. fewer bids than 4 other conferences)
Then of course the "new" narrative was the ACC being underrated (e.g. 4 teams making the Sweet 16 supposedly an attestation to its veracity).
And once again, you can counter that narrative (i. "is it really an underrated conference, consider these outcomes, ACC reg. season loses to SEC 3, etc.)
Which is what he's getting at... you can make the case for any of these narratives depending on what evidence/data points you cherry-pick, more or less. Which of course is inherently flawed.
Again, I may be wrong but I think he's saying narratives are difficult because they are often rooted in a fundamentally flawed methodology.