URLs from RT should be redirected to the Phabricator URL and whatever numbering scheme we decide to go with so that there aren't collisions with tickets imported from Bugzilla (T65).
Are there other redirects we'd like to have, apart from tickets numbers?
**Update**: RT has several queues, and two of them will not be migrated yet. For this reason, automatic redirects from rt.wikimedia.org cannot be created until the two remaining queues are migrated as well. Resolving as "Open, Stalled" for now.