"Woops. I hit ctrl+enter instead of ctrl+c while copying my secret. Guess production's down for a bit while we roll new ones!"

I mean your core idea is decent but that's just really funny.

There's some amount of practicality being lost if your secrets start growing massively. There's also potentially restrictions to what you can put in them, and a prefix with an underscore or colon might be easier than something that has slashes in it.

Your idea is probably living as a queriable dns record on the domain in question. Or a standard subdomain, or even a .well-known path.