Some strings are converted to links in comments at bugzilla.wikimedia.org. This is a functionality that comes out of the box in Bugzilla to mark links to other Bugzilla reports, ans the we have extended in order to link to i.e. Gerrit changes and wiki pages.
These conversions can be done by a bot. We need to define which strings need to be converted in links.
Also, we need to agree when to run the bot. Since this is a time consuming activity for a bot, and these links are not critical, probably the best idea is to reopen Phabricator after the migration with this task pending, and then let the bot do the changes at their own pace. Users will see the plain text first, then at some point the links.