> not that you assume that the types of changes that can happen in a type of bump will happen
reply… an assumption that something happened is not a definitive statement that it did happen, only that we're assuming it did, because it could happen, or perhaps here, that because the major was bumped, that it is legal, according to the contract given, for it to have possibly happened in a way that we depended on. They're not saying that it will/must; "assume a major version is incompatible" is not at odds with what you've written.
You and I have a very different version of what the equals sign means. "This is a reasonable action to take in this scenario" is not what I understand as equivalence.
replyPerhaps I should have used an implication sign -> instead of an equals.
replySemver says “major version MUST be incremented if any backward incompatible changes are introduced to the public API.” You’re correct that it doesn’t say “major version MUST NOT be incremented if there are no backward incompatible changes”, so technically that is possible — but it would be a very odd thing to do.