The only thing that breaks follow in Arena today is the blanket "PvP combat breaks follow" mechanic, which wasn't carried over to Classic, and so it may not be carried over to TBC Classic, since it seems to be a system that was really only implemented due to Retail's War Mode. So... multiboxing Arenas in TBC may actually be a thing, and that'd be very interesting. Blizzard was willing to specifically re-implement follow in Arenas after they removed it from both there and battlegrounds, so I'd say that those looking to do TBC Arena have a good chance.
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