I think everything you said is totally correct for open source library owners.

But let me offer a different perspective: Hyrum’s law is neither a technical contract nor a social contract. It’s an emergent technical property in a sufficiently used system.

How you respond to that emergent property depends on the social context.

If you are a FOSS maintainer, and an optimization speeds up 99.99% of users and requires 0.01% to either fix their code or upgrade to a new API, you ship it.

If you are working at a big tech company, you need both the optimization and breaking 0% of the company. So you will work across teams to find the sweet spot.

If you are an enterprise software company, and you change breaks 0.1% if users, but that user is one of the top 5 contracts, you don’t ship.