OK, reality check time.
Yes, the design has a weakness that shows up at times. I own or have had all three Dxxx series Denon's and never had a problem, as well as owning the TH900 now with not one problem.
Many headphones have design weaknesses - the supposed "tank-like" M-100's have the cracking wing plates.
I would not spend much time worrying about these failing, but as always, do your due diligence and check the tightness of the connections, and if need be, tighten as needed.
Not everyone is comfortable taking these apart, but really, it's not difficult once you get past the fear stage and start working on them. Simple design and easy to assemble/disassemble and parts are available if needed to repair. There are YouTube videos to help, and I'd be happy to help as well, as I'm sure many would.
The sound of these to me makes any weakness minor in my mind. And sure, many may feel a $1300 headphone should not have any flaws, but manufacturing is an imperfect deal, in any and all industries. Been doing it for 30+ years and from simple plastic milk caps to complicated shop heaters, the old adage of "schiit happens" is true.