We should update the Phabricator deployment submodules repositories to point to the canonical GitLab/Gerrit repositories instead of the diffusion mirrors.
More or less related is https://phabricator.wikimedia.org/source/phabricator-translatewiki/ though it is not part of the phabricator/deployment repository (and is disabled and inactive)
For the records, there is also the (deployed) extension https://gerrit.wikimedia.org/g/phabricator/antivandalism/ with its canonical code repo still on Gerrit (instead of most other Phab repos being on GitLab).