Surely this is true, but if you’re a fingerprinting company aren’t you making so much money violating the privacy of the masses that it’s not worth your time going after the tiny set of Freedom Nerds trying to evade you?
They aren't specifically going after you... they just try to create a unique hash from everything they can and by doing weird things to your system you are making a truly unique hash easier
You can change the header, but browser developers are not that dumb and they added properties like "navigator.platform" which do not change and immediately give you away. Consider also writing a browser extension to patch these properties. Also, I think that DRM module (widewine), that is bundled with browsers, also can report the actual software version. Sadly it is undocumented so I don't know what information it can provide, but I notice warnings from Firefox about attempts to use DRM on various sites like Yandex Market.
The article also mentions this, and suggests the UA is not a silver bullet. That said, they didn’t go into specifics. I’m assuming there are other details that correlate to particular browsers that will betray a false UA. Plus, having a UA that says Chrome while including an extension that’s exclusive to Safari (tor example) will not only contradict the UA, but it will also be a highly distinctive datapoint for fingerprinting, in and of itself.