I think it will be interesting to see how quickly they adopt Rebellion-only brawl frays. I would think the easiest fix would be all the current "modern" frays (CL set + U set) stay modern frays (CL set + Reb set). If there is a CL only fray, it should become a Reb only fray. The Untamed set will just get pushed over to the Wild frays. A/B only should remain as well. Seems pretty simple and syraight forward to me!