I think his point was related to adding the players of the DDR post-reunification. Of course, it was still a bit silly because the only player from that pool who made a significant impact in the 90s was Sammer, but obviously there was a good bit of post-World Cup arrogance there.
There was actually a similar article in the Sport Bild just after the 2014 World Cup victory. I forgot the exact header but it said something like "How Germany Can Dominate For Years To Come". I was shaking my head at it even then.
I remember around 2011-13 there was so much hype about the 'next generation' of stars, and how Germany was just so awesome at talent development now. That was based on guys like Götze, Reus, Draxler..notice how it's 6-7 years later and people still talk about them as the 'next generation' even though they're no longer youngsters. What people will discover over the next months of inquiriesis that German production of elite players has once again dried up a bit since then. There are of course talented players, but you can't count on them to all become world class players. It's a bit cyclical naturally..because the already existing crop of established stars occupy spots and thus limit the opportunities for the younger players.
I wouldn't be shocked to see the German team go off a cliff once the late 00s generation starts disappearing (and it may already have begun in this World Cup) i.e. the likes of Özil, Müller, Boateng, Hummels, Neuer, Khedira, Kroos.