All of tasks to remove as many forks or sync as many as possible packages with SLE should ideally not happen close to GM deadline. These should be most likely all accepted in RC.
Last time we took in a relatively tested SLE submission and it backfired as systemd (and possibly others) could not be rebuild.
Keep in mind that packages coming from :Update are generally more risky as they do not rebuild as part of :GA. Therefore it's hard to say if package rebuild.
All of tasks to remove as many forks or sync as many as possible packages with SLE should ideally not happen close to GM deadline. These should be most likely all accepted in RC.
Last time we took in a relatively tested SLE submission and it backfired as systemd (and possibly others) could not be rebuild.