Assume the covers being referred to would be the wheel arch liner? Can't really comment on the differences (if any) between the wheel arch liner on the mk7 and mk7.5 Golf as I don't have either. However, your video clearly shows the mk7.5 does have a wheel arch liner that will protect the underside of the wing / fender from general road dirt and winter salt spray, so it should do the job it's intended to do.
As for the comment made by the person watching your video that cost cutting should be forbidden by law; pretty much all companies will have an objective of ongoing cost management and profit maximisation. If VW can reduce costs without materially adversely affecting the quality, safety or performance of the end product, why wouldn't they? They won't be the only company that does this.