HP Too, Dell keeping 17.3 inch
HP have done the same with their Zbook Fury range they will now only offer a 16.0 inch model which like the Lenovo is pretty much a 15.6 inch chassis with a slightly taller screen. However Dell have gone to Precision 7670 16.0 inch but have also kept their 7770 17.3 Inch.
From what I hear Dell have far more volume in the Workstation market so it may well be this is the reasoning behind the changes.
I'm not convinced that you can cool the ever more powerful graphics like the A5500 topping 150W as well in a 15.6/16.0 form factor especially with the Cpu demands also increasing. so for me the 17 inch form factor is going to my choice for performance until I can test options.
Having said that I have the current Precision 7760 17.3 inch myself putting it up against a colleagues 7560 15.6 inch chassis it is a significant size difference so for hybrid work the smaller size is likely a tempting factor!
Dell have also added a 14 inch 5470 which looks similar to the XPS range but is exclusive to workstations so seem to be going the opposite way and adding more form factors.
Also of interest is that Dell have worked with intel to create their own thinner single pcb CAMM memory format rather than using 2 or 4x SO-DIMM. I believe this gives them more space for cooling and may smaller chassis in futur.main downside is upgrades mens removing existing Ram, and to get ECC Ram you have to use an inteposer and are limited to 64GB ECC. Dell are hoping CAMM will become the new standard but time will tell.