Here are the three general problems with submitting print views:
1. For most sites, the print view results in a small font and lines that extend all the way across the page. This makes them hard to read. Sometimes, on a desktop, with a bit of fiddling they can actually be made legible to those of us who are older than 40. On mobile, they are often simply not possible for many of us to read.
This particular site is OK in this regard, as they appear to have actually set the line width and the font size so that it comes out reasonable on the screen. In fact, their print view is quite pleasant to read.
2. The print view often omits comments, sidebar links to related stories, links for sharing, and so on. Some people actually might want to use those.
3. There is often no evident link from the print view back to the normal view. Sometimes you can figure it out by playing with the URL, but sometimes the relationship between the print URL and the normal URL is hard to figure out if all you have is the print URL to work with. Note that the normal page, on the other hand, does generally have a link to the print page, so those who prefer the print page can easily go to it.
For these reasons, in almost all cases the submission should be to the normal page, not the print page. Ideally, the submitter can add a comment that gives the print URL to save time for those who do prefer it.
Note that some sites have an "all on one page" option, that puts the whole thing on one page, but leaves comments, social links, and such. That's the best to use if available.