Only switches between major versions "could" contain breaking changes or not depending on the particular case.
However, this project tries to keep away from any kind of breaking change possible between major versions. But it still supports and prioritizes "no breaking changes" for minor and patch (bug fixes) versions.
On the other hand, if a breaking change is found to be "strictly necessary" to do. Then a new major version must be promoted as well and users informed accordingly so they can do a seamless transition.