from who is this rumour?
I hve no idea either. The rumour that a 2 exists has been floating around but I dont recall anything specific to PGW. Makes moer sense for PSX if you ask me.
Last PGW we got GT Sport, UD Rush of Blood, Detroit, Driveclub Bikes and Matterfall were all announced.(plus some other random stuff)
i may think it will be more VR focussed this time around but their EU pressers usually have some cool games announced (especially SCEJ at gamescom events)
On the official PlayStation All Stars forum there were some rumoured leaks shown, aswell as the PlayStation All Stars trade mark renewal which also falls in line with a leak from a few months back.