I can't even imagine the maintenance or repair considerations of a pack that's embedded inside of the frame or a monocoque chassis.
Lastly this isn't even an Ars article, it's from Wired. It really is a terrible click-bait headline. The article, imho isn't much better.
It's terrible for repairability, and with regards to power sources... safety.
This is a bunch of researchers solving the wrong optimization problem. You'll likely see it in Formula E, but under no circumstances should it be in production, mass-produced cars.
https://cleantechnica.com/2020/10/10/teslas-new-structural-b... (Tesla’s New Structural Battery Pack — It’s Not Cell-to-Pack, It’s Cell-to-Body)
What OP's link is describing, is where the battery cells literally are the vehicle trunk - as in they're built into the walls, instead of being contained between two walls.
Yes they do. The first paragraph of this article discusses Elon Musk talking about integrating this into Teslas.
Gizmodo stylee