I'd be interested to know how long it would normally take a manufacturer to design a new cab layout, test it, get it crash tested and start making it and selling it.
Doesn't really matter since refuse trucks have had high visibility cabs for decades to prevent them running over their own staff. There are probably some edge-case HGVs that can't use a similar cab for some reason but the majority would be fine with one.
I'd be interested to know how long it would normally take a manufacturer to design a new cab layout, test it, get it crash tested and start making it and selling it.