I suspect your question is essentially "why is this 14.0, and not 13.3?" And the answer to that question is that this is a new release from our development branch, not an update to an existing branch used for the 13.x releases.

FreeBSD 14.0 represents over two and a half years of feature development, stability and security improvements, and bug fixes. Some of these changes were cherry-picked into the stable/13 branch and were included in the FreeBSD 13.1 and FreeBSD 13.2 minor releases built from there.

A sibling comment notes that APIs or ABIs may change between major versions. This is true, but this is not the reason for a new major version. Rather, ABI and API changes are allowed during the development cycle on the main branch, but are not cherry-picked into the existing stable branches.

I have a proposed change to include in the release notes some significant changes that happened to have been merged into 13.x already, and so far have been excluded from 14.0's notes: https://reviews.freebsd.org/D42546