And I agree it's a fairly obvious risk if you stop and think about it, but it's not necessarily true that losing access to a feature, which is a reversible state, also permanently deletes all configuration data associated with that feature.
Regarding the branch protection feature, I can see it both ways, but I think overall I would have not expected them to be re-instantiated when upgrading to a higher tier again. Branches could have changed since then. I could have added more branches, deleted a branch which previously had the protection, then maybe created a new branch under the same name, etc.
Unless it's an immediate "I accidentally downgraded, revert all changes back again" action I think it's easier for GitHub to just let the user re-create what makes the most sense for them at the point of re-joining the higher tier. But like with most user features it's debatable...
They then further go on to say, "... when upgrading back to a Pro account, any branch protection rules you had before were permanently deleted when you downgraded to the free tier. They will all have to be recreated from scratch."
That is useful information, to me. People write blog posts about all types of things that are obvious to some and useful to others. Why be so nasty about this short post that seems to be useful to a lot of people? I guess that's 2019 for ya.
It's easy to ask snarky questions. That doesn't mean it's helpful or witty.