Unfortunately with stuff like this Hyrum’s Law happens at a distance and in aggregate. And 429’s are clearly not part of that living contract.

The reality is that it’s not much effort to serve a small bit of plaintext data, and nobody really cares that much to even notice.

It’s unclear if the effort is worth it, for anything other than what amounts to “well ackchully the spec says I can do it so I’ll do it” pedantry.