I guess I should own up on calling 6.5 CM one of the newest calibers designed for long range shooting. I did not realize that the 6.5CM came out in 2007. That is a long time ago. I don't read gun mags every month but do read them occasionally or whenever a buddy talks about some new caliber or there's an article about something to do with a game species that I hunt. In looking through your above list of calibers, I can see that the gun mags ignore several of those 6mm's and most of the Nosler cartridges. Comparing a cartridge to the 308 gives a baseline of performance for many of us. That doesn't mean half of any article should be about a .308 but I can see where listing it in a title is going to draw more attention.
My interest in long range shooting is about calibers and cartridges used, what makes them more competitive and why. It's fun to learn new stuff and see what direction competitions are moving a class of rifles and cartridges. I don't know that any of the new cartridges are going to make a difference for me in hunting or plinking but it's interesting still to see what people are using to remain competitive at longer ranges.