The list of official mirrors changes regularly and ubuntu-release-upgrader will switch a user to their country's mirror if the mirror they are using is no longer an official one. Updating the official mirrors is something that should definitely happen for LTS releases.
The list of official mirrors changes regularly and ubuntu- release- upgrader will switch a user to their country's mirror if the mirror they are using is no longer an official one. Updating the official mirrors is something that should definitely happen for LTS releases.