Software is arbitrary. Any so-called "guarantee" is only as good as the developers and organizations maintaining a piece of software want to make it regardless of prior statements. At some point, the practical likelihood of a documented, but not guaranteed, process being violated vs. the willful abandonment of a guarantee start to look very similar.... at which point nothing saves you.

Sometimes the best you can do is recognize who you're working with today, know how they work, and be prepared for those people to be different in the future (or of a different mind) and for things to change regardless to expressed guarantees.

....unless we're talking about the laws of physics... ...that's different...