I also saw this. What's strange is that it showed 1.14 for me too, which makes no sense. I've visited that page 6 months ago to install go1.15, the current version on my machine, and anyway I completely clean my browser cache every few months, so there's no way I had a 1-year-old page cached.
After forcing a clean reload of the page with Ctrl+Shift+r (firefox) it fixed itself, so yeah. Not sure what the problem is.