I think how one interprets the usage of “square pixels” here is highly dependent on what that person is most familiar with. When I saw the title, even without reading the article, I immediately knew it’s talking about PAR, since I’m already familiar with video encoding standards. It didn’t even occur to me that it could be talking about the shape of physical elements on various display technologies.
Well technically it's like a "subscription with indeterminate renewal cycle". Every few years they release a new major version and sometimes you have to pay to upgrade.
Of course you can choose to not upgrade... but then you don't get the new features, and it's unclear if the old version will support all newer macOS releases.