An exciting time much like the late 70's when Runequest and Chivalry and Sorcery and Tunnels and Trolls all made a splash ... and the 80's where the mighty Avalon Hill released Powers & Perils, plus GURPS was new and Fantasy Hero was new ... and the 90's where FASA - FASA! - put out an actual fantasy RPG called Earthdawn ... and the 2010-ish era where we saw Pathfinder and 13th Age and Shadow of the Demon Lord and Dungeon Crawl Classics and others who were capitalizing on the perceived lack of enthusiasm around 4E D&D, not to mention the OSR thing snowballing right along.
I know not everyone was around for the entire history of RPGs but all of these things were thought of as big deals at the time and many of them went on to at least moderate success and many have some version in print today. None of them "de-throned" D&D and it is extremely unlikely that any of this new wave of OSR-Fallout games will either. It's also very premature to start speculating weeks and months after their release. There's nothing wrong with being excited about new games - there are new ones every year, especially Fantasy games - but the hyperbole is strong with the OP.