You are wrong on the power supplies...

It is mentioned in several videos from CES that power supply configuration will be based upon CPU/GPU combination in the laptop. The configurations are as follows:

180 / 180
180 / 240
180 / 330

Quote from: Redaktion on January 08, 2019, 19:06:19

Dell is pulling a Clevo by offering a laptop with desktop CPU options and an upgradeable GPU. Instead of adopting the MXM GPU form factor like MSI and Clevo, however, Dell has created its own proprietary DGFF GPU form factor that promises better support and easier serviceability.

"Dell says Quadro GPUs will not be supported as the Area-51m will focus on games. .... If the DGFF form factor takes off, however, we wouldn't be surprised to see future Precision laptops adopt the concept in some way."

Dell has already updated their Precision 17 and larger 15" laptops to use DGFF since their release almost 6 months ago.

A user confirmed on the notebookreview forums that their DGFF Quadro P3200 is a different shape and layout, and will not fit into the Area 51M

This may have more potential than it did in the past, bridging SFF to notebook systems combined with parts that don't quite consume the type of power they did in the past (meaning you get a lot more cpu/gpu capability per watt that may well make this design successful or at least coexistent with laptop tech).
From what I can see one of the areas they could stand to improve slightly would be to have an external power button when the lid is closed.  I do kind of wish this on most AW laptops as they are used in a docked station a lot more these days now that TB and Amplifier make that process so easy.  Admittedly there is a difficulty of where to place such a button such that the device does not get turned on while in a case/bag, but I'm pretty positive they could solve that.
I certainly find this device curious.