ESRI Basemaps are great, but when they're used in a map layout designed for print the resolution is simply not sufficient. It would be great if we had the option of requesting high resolution map tiles (>200 ppi) when exporting a document to PDF.
If anything, the referenced technical article only reinforces this idea. Firstly, it isn't possible to adjust the resolution so proposing it is possible is a request to change the behavior of the software. Secondly, use a Data Appliance for ArcGIS to get better print quality is an absurd suggestion for most customers.
Yes, it's clear that it isn't possible, and the Idea is valid which is why it is marked as Reviewed and open to voting. The reference to the article was because it provides some explanation like "Most cached web map services such as those available from ArcGIS Online are designed for viewing on the screen" and "The basemaps are provided as services, thus such behavior is expected." Maybe it isn't necessary here, but I usually try to link to documentation, technical articles, other sites, or show screenshots that provide additional context to an idea rather than nothing.
Have you tried their vector base maps? I just tried one in a PDF export and the output looked really nice. And you can adjust the colors/styles/fonts, though I'm not sure how to bring a custom vector base map into Pro.
