The way I've heard it described is that it's a win-win for us no matter what happens at en banc.
In the past, the states have opted for en banc, and won those cases. If hawaii loses en banc, they won't appeal to the SCOTUS. They'll "take one for the team" to possible avoid wider 2nd amendment implications handed down at the federal level, and CA and HI gets open carry. On the other hand, if the 9th circuit overturns the ruling, (presumably) young will appeal to SCOTUS and get a nationwide rulling on carry, which could be very unfavorable to gun opponents because of the shifting composition of the supreme court.
Assuming Hawaii loses en banc, following the ruling, Hawaii should find it in their best interest to go to "shall issue" concealed carry. The ruling says that there needs to be either open or concealed carry available to the law abiding masses. They don't want the massive headaches and police calls as fear grips people's liberal hearts if they allowed open carry. It is in both gun advocate and opponents best interest if people is concealed carrying. So they will keep open carry banned, and allow concealed carry on a shall issue basis.