More info can be found on their community pages here: https://community.atlassian.com/forums/discussion/3234032/upcoming-change-to-bitbucket-cloud-ssh-access-move-from-bitbucket-org-to-ssh-bitbucket-org#M2952
Despite the date on the community post it only seems to have been noticed within the last few weeks which has caused a little bit of panic as "bitbucket.org" has been effectively hard coded in to pipelines and other places.
Additionally non of the documentation and support material have been updated. The API and clone buttons still return the old bitbucket.org address instead of the new ssh.bitbucket.org.
What's your plan for fixing this on your systems before the 12th of November 2026 ?