It has been reported that Aiba Masaki has returned to work on July 5th after being hospitalized a few days prior. He showed up to filming for the VS Arashi program and while he was present did not participate in the physical games on the program.
Tokyo Graph article. (English)
I'm sure everyone is glad that he's doing much better and is taking things easy still. Arashi still has a busy year ahead of them, especially with a tour but it sounds like he'll do his best with making sure he doesn't push himself too much and I'm sure his fellow group members and staff members will be looking out for his safety too after this.