Steve Burke from GamersNexus is known to have friendships with industry insiders / board partners (ASUS, MSI, Gigabyte and CoolerMaster), as shown by his exclusive footage from inside manufacturing facilities in China etc. It looks like Nvidia is planning to announce and/or launch the first RTX 3000 cards on September 9th or close to it. It's possible they'll announce it a bit earlier at Gamescom in late August, however the event is now online only due to the COVID outbreak, so it's more likely that Nvidia will have their own event.