I wouldn’t go that far. Instead I would say that it could be right but the evidence is much weaker than I thought it was 8 years ago.
A few things that convinced me:
A slatestarcodex series on mindset:
no clarity around grown mindset
clarifications on the last post
a pox on growth your houses (scott is really good at titles) and the response
A large preregistered study on growth mindset maybe showed a small effect but nothing like what proponents claimed.
And generally my trust in the kinds of small n social science experiments that were the backbone of growth mindset research and similar things like priming is just much lower—my prior is now that those things are mostly noise, and so the evidence needs to be stronger to overcome that, where that wasn’t true 8 years ago.