It isn't worth it for either of those funds to play hardball over $400k when hundreds of founders will read that, and will ultimately decide if they want the fund on their cap table for the next Uber/Lyft/Data Dog/Airbnb/etc.
I said it before, but it's worth repeating - SV runs on relationships.
Baremetrics and Josh are known for their hyper transparent blog posts. They even publicly share all their revenue metrics. It’s highly likely the firms knew Josh would write a blog post about the exact exit terms.
He mentions his VCs have always been available and engaged, so I think it's reasonable that they knew he would be open and public about the deal; he always has in the past.