Gabriel took the bow for what it was. Cautious acknowledgement and greetings intended for a man he no longer was. For all intents and purposes Reyes was dead. That part of his life had led him to an untimely and unpleasant demise. He wasn't interested in reminiscing about the 'good ol' days' because 'good' was really just a matter of perspective. Years doing Overwatch's dirty work (the work he'd had a hand in making dirty) could take a toll on anyone's personality and moral code. Dying, and then winding up not exactly dead but not exactly alive did the rest of the work to fashion him into who and what he wanted to personify these days.
"Some faces are better left behind their masks, Shimada." He'd leave it at that. It was a stretch to say they'd been particularly close in Blackwatch, though he'd grown to respect most of his agents before it all went to shit. Shimada was an outlier in his own way. Not exactly befitting of Overwatch but not exactly suitable to Blackwatch either. He'd towed the line, and it was maybe the only reason that Reaper hadn't been gunning for him from the start. That, and making tentative allies based purely familiarity because he was in unfamiliar territory wasn't a bad thing.
"Sometimes people get lost in the woods. I'll let people's imaginations decide what monster's responsible." Never directly admit to anything. But if Genji knew anything about his condition he knew that Reaper left husks in his wake. The longer he went without feeding the more unpredictable he became. Better to pick out the sick and the weak parts of the herd than the whole bunch just because he couldn't rein himself in.
"But before your bleeding heart decides to get heroic, I'm not here to feed. I'm here to see just how pathetic their pathetic excuse for a tournament is."