Comment by tantalor
Nope. You have to remember https://www.hyrumslaw.com/
With a sufficient number of users of an API,
it does not matter what you promise in the contract:
all observable behaviors of your system
will be depended on by somebody.
And then you can never remove it!
Semi-related: this type of thing is actually covered in the Site Reliability Engineering book by Google. They highlighted a case of a system that outperformed its SLO, so people depended on it having 100% uptime. They "fixed" this by injecting errors to go closer to their SLA, forcing downstream engineers to deal with the fact that the dependent services would sometimes fail for no reason.
I know it's easier said than done everywhere, just found it to be an interesting parallel.