True. Linux machines don't read articles though, people do. Whether any randomly selected linux-using reader will have cups installed on a device they control is a very different question.
Any randomly selected Linux machine is most likely to be a mobile phone, statistically speaking
Are you sure there are more Android phones than Linux servers?
I don't think there's a way to check for sure but I'd say that's pretty likely. There are billions of android devices, and Linux servers, while popular, are probably less common just because servers are less common than consumer devices in general. But maybe I'm wrong!
I'm pretty Android doesn't use CUPS, and most people that use Android don't consider themselves Linux users. I think it's okay.