What it comes down to is a definition of arena viable. Can BH win on offense, yes.... SO yes you can use them in arena.
For me, for a team to be arena viable he needs to hold on defense, if you drop from 5 to 50 overnight its not great. Which for me means it is not an easy win when put on defense for 50% of the player base. Boba lead BH (with or without vader) are easy pickings for ZVader or NS squads. OR even EP lead squads (there vader with easily outspeed you). Given that many players have those sqauds as an option, I do not seem BH holding on defense.
I have not come across any BH teams in my arena. I know one still active player had a zBF lead BH team a year ago, he has not dusted it off yet.
Bounty Hunters are still a solid team for DS TB, and TW offense...
