Just curious, around how long ago was this change made? Can you find web.archive.org links for a page which was changed? I'd find them useful for discussions with my peers.
The gpg approach was available in September 2017, when I used it to setup my account. I can't tell you any better than that though, and that's part of the nature of opaque aggressive growth startups today. Things just disappear or change with no acknowledgement of the past unless it's part of the story the company wants to tell about itself today. It's reasons like this that I tend to lose all interest in a project as soon as I hear they've taken VC.