> Perhaps they’re afraid announcement would trigger divestment
S&P don't get a choice around whether they announce their methodology or not.
That said, the rule change at the NASDAQ 100 doesn't seem to have impacted pricing or allocation. I can't imagine that many people are that concerned about this. (I posted the public-comment request from S&P to HN [1]. The response was crickets.)
Just yesterday I asked my advisor about exposure to these IPOs.
I don't mind having a small bit of exposure to them, I just don't want the outsized share they seem to be trying to take for everyone.