Canonical’s announced a major shift in its kernel selection process for future Ubuntu releases. An “aggressive kernel version commitment policy” pivot will see it ship the latest upstream kernel code in development at the time of a new Ubuntu release.
Original announcement: Kernel Version Selection for Ubuntu Releases
Why would they start providing their own kernels?
All this change is that instead of choosing the latest stable release at the time of Ubuntu’s kernel freeze, they may choose to use the in-development kernel if it’s expected to release before the next Ubuntu release.