I would think (and what do I know) that a beam in BeamNG is a solid object, and the car is interacting with these beams as if you are pushing your car with your torso (we've all been there lol)... or rather, the beam is interacting with the beams on the car.
Doesn’t look necessarily like it’s a walking mode as much as a sort of revamped switch vehicle type thing. That’s my opinion and you are free to have yours
The last time we got frequent teasers in update speculation was... the day of the update. I highly doubt it's today, it feels way too early.
I can only assume with the walking mode being made, they wouldn’t do it without career mode being near, and probably closer than we expect