I think these are a great idea for a wide range of vehicles.
Although I do disagree with the statement: "working with a chassis that only needs to be crash-tested and approved once to be relevant for a broad range of vehicles".
There's more to crash testing than just the bottom chassis. The entire cab comes in to play, so every configuration will need tested for safety. An advantage would be that they could possibly test them with a chassis that has the motors and batteries removed to save costs. Maybe even use quality rejected motors to exactly simulate structure. Batteries may need to be in for some tests, to make sure there are no issues with shorts in crashes.

Is all the mix and match only at the factory? I'm imagining a setup where I could just unbolt the interior (except for maybe two front seats/dashboard/winshield) for carrying large objects. Reconfigure for camping. Bolt on high-clearance corners to go off road...

Nah, probably not in the cards, but it would solve the crossover problem.

No mention of battery size, range nor recharge rate. I assume that range will depend on what is built on top of the platform. I think a quickly swap-able battery setup would be an advantage if the range is less than 1000km.

I'd like to see a connected link in steering wheels and linked steering, braking as just too important to leave to electronics, as an electronics tech.
And in EVs having correct alinement of the wheels is not an option as greatly increases drag. On my EVs I don't use tow in/out which I set to 0 because of this.

So how will this work when running in mud or snow? Nothing like a little road salt to short out the electronics.

18 wheelers big trucks will be crushing these on the road, too low not visible definitely not safe they may have their place somewhere maybe distribution or transport inside private property or warehouse

Where do you sit?

Should be made the size of a freight container.

Very interesting.
Looks like REE may have made the leap from vapor to reality.
One complaint regarding the promo video -
Like so many other EV promo videos, there is a blaring sound track that drowns out one of the key features of EVs - the silence!

Surely any superstructure is going to have to provide torsional rigidity. Right? I wonder how they've designed the connection points between the skateboard and the cabin / bed. A modular platform is pretty interesting...