They recommend Quadros simply because they are officially supported by Nvidia for this type of task. IE if your card acts funny in ArchiCAD and you have a Quadro, Nvidia will help. If you're using a GeForce, they won't (or they will, but very slowly).
In most cases the GeForces are just fine though, it will be a very nice machine for ArchiCAD.
All of the other specs are good - possibly verging on Overpowered, but that will mean it gives good performance for quite some time.
The only real problem is the screen 1366x768 is very low resolution, especially for a 15". I have a 10" laptop that uses that resolution!
For a 15.6" I'd want to get at the very least, a 1440x900 screen, although 1680x1050 would be better.
If you'll usually be plugging into an external monitor anyway, then the lower res would be fine though.
Josh Osborne - Central Innovation
HP Zbook Studio G4 - Windows 10 Pro, Intel i7 7820HQ, 32Gb RAM, Quadro M1200