I'm sorry, but I do not understand where you are coming from. Shouldn't these "flu masks" also prevent people from interacting with each others, similar to how you argue that burqas should be banned because of this very same thing? Banning a specific religious garb is oppressing. I'm not surprised that China does it, but any democratic sociaty shouldn't. Better to ban ALL masks in that case.
typical flu mask:
I have nothing against the Hijab or the Chador other than that they make women look worse than non-veiled (sort of their purpose) and I don't agree with China banning those. But I don't consider the Niqab or Burqa "religious gear", as it's use is an enormously strict interpretation of some suras and hence it's only enforced in "fundamentalist" sects - it just takes the arabic tradition to seclude women from society to the extreme.
And as I said again, again, again and again, the problem I see is when people wear those every time they step outside of their houses, I can even accept niqab and burqa, if they were only used during the highest muslim holidays/ a few days a year, but they aren't.
Outside of muslim/arabic women wearing those special garbs (and maybe some small tribes I never heard of) hardly anyone/ only very few individuals mask their face in such an extreme way every day and towards pretty much everybody they encounter - an overwhelming part of the population realizes instinctively that showing your face is the minimum requirement to take part in society, so a ban to everything that masks the face (with probably exceptions based on special circumstances) is superfluous legislation.