Araki got married this summer, so I think that she's got the summer off and I doubt that she'd be playing with the team at the Asian Championships.
I would think that Japan is going to go with a "reserve" squad of the remaining players from the World GP roster.
For me it's not really reserve roster, Miyashita is doing nice job and when necessary Hashimoto can replace her Wing-spikers also look good, though Ebata could have nice replacement in Sakoda, fortunately there is OPP Nagaoka and then Shinnabe can play as OH like she did it in V-League. Only weakness here are middle-blockers and Araki could be a sigh of relief