I assume it is a recent push toward these kind of open frame, super minimalist, consumer hardware based systems (I don't speak german and didn't translate the video).
It looks like they're using lots of consumer hardware and very little redundancy; you'll notice that the power supplies are generic ATX units and they're not doubled up. And then they're also running the onboard networking with a second connection which looks like it's for just a management system. Might not even be 10 gigabit networking.
It's interesting that in an era where almost all of the major players are moving toward cable-free arrangements i.e. backplanes with fully integrated power and networking, etc., they're instead opting for the rat's nest of cabling. It must have something to do with lower labor costs vs hardware costs. The amount of density that they are achieving with those systems is also incredibly low relatively speaking.