I don’t think it was a hack, rather it was a real test. The dev mentions it in this tweet https://twitter.com/levelsio/status/1377687358095654914?s=20
I think The Lean Startup was the first to popularize this idea, maybe? It’s nothing new, although I’ve always found it a bit weird/distasteful. I’m surprised he’s okay with doing it on his established brand where there is actually something to lose (vs spinning up a totally new site with no existing brand capital).