I think Twitter, err, X, just turned off the delay now that it's getting big media attention. I could reproduce it over and over again a little earlier, but now I can't anymore: https://news.ycombinator.com/item?id=37138161
[Edit:] I'm still seeing it with threads.net:
curl -v -A 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/16.6 Safari/605.1.15' https://t.co/DzIiCFp7Ti
[Edit:] I'm still seeing it with threads.net: