People use WhatsApp on the computer? From the Windows Store of all places? Must be a tiny percentage, which is why this version is now a basic web wrapper now. Anyway, I’d remind everyone that “using” RAM doesn’t mean “would not function with less RAM.” Many applications just use a lot if it’s available. RAM is not really something you explicitly ration.
Also, even in theory the issue isn't only with "wouldn't function", but "would function slower due to eg disk swaps / cause other apps to function slower".