I wonder? "Bluey" as the Scala is now "officially" named by my grand daughter, does it's updates over the air. I just confirm it to do it by tapping the request on the "TV" screen on the dash. Sometimes it says "do not drive vehicle whilst updating" and advises you to authorise it overnight.
I do wonder if the reason they could get into the steering only is it has the Nissan pro-pilot system and I believe that can be over the air updated, perhaps it also sends and receives live data.
Do not drive while updating maybe more to do with for example losing the virtual instruments while travelling.
One of those things it may be always on but in theory the engine bay ECU and anything steering or brake related could not be connected directly to the online part of the car. Would make any updates a dealer job but I'd bet 99.9% of updates needed cover nav and infotainment things which in theory the car works without.