I wonder what purpose this particular dark pattern serves?

Edit: Perhaps accounts that authenticate on this page, and that are also taking advantage of free tiers, are being segmented for upsell. It is at least an indicator they are interested enough to read this news.

I’ve noticed the AWS Forums does this too. In practice it just means I avoid using it.

Could just be a caching thing? I know most `help.heroku.com` pages are customer-only (as opposed to their public-facing docs at devcenter.heroku.com). Maybe they have a very rare "publicly available" option that doesn't see a lot of testing