Pantone did invent their names for colours. You can use the colours, but not their names. These files are using their names is the issue. If the file used their own names or raw CMYK values it’s be fine.
Does that matter if the thing being designed is gonna printed by a cmyk printer or displayed on a screen? And more: does it matter if the color is 1/3 of a lumen off from whatever was shown on a screen that was possibly not even properly calibrated?
If you pick up a pantone book and flip through it, they put their colors opposite CMYK equivalents. Sometimes they barely resemble each other. CMYK is optimally expressive, not maximally expressive. To make all the pantone colors requires a wall full of sloppy cans of paint to be mixed through a book of arcane formulas. To make a CMYK color, you need four cans of paint and four percentage values.
edit: anybody who thinks the gamut of CMYK is anything like the gamut of Pantone, try printing out something purple on your printer. I worked prepress, and trying to get a good CMYK purple is my idea of hell.
Generally no, it doesn't matter if you're just displaying on (mostly uncalibrated) screens, or printing in CMYK on normal paper stock. It gets more interesting if you're producing things like brochures, in which you care about the texture and technique used to apply particular areas as well as the colour itself. Thing about things like the glossy lettering on a brochure which can't be represented as a set of four colours.
And the fact is that a lot of designers can get incredibly anal about tiny details of color/texture/etc. I remember back in undergrad when I was doing some press work, there was one poster that the designers had specified two different (Pantone) shades of dark neutral ink and I doubt anyone looking at the poster saw anything other than "black" for both of them.
And before any developers throw shade on this sort of obsessiveness, remember stones and glass houses.
I picked up a love of design obsession from the years I spent working as a developer in design agencies. A lot of it is very much focused on how a thing feels to whoever receives it, even they don't consciously notice that happening. Stuff like the paper stock or binding is only ever going to excite a professional designer, but even people with no education on this at all can tell the difference between a glossy brochure with thick textured pages and a cheap flyer printed for as little money as possible. Some companies even target the latter because they don't want to give the impression of being a luxury retailer.
If you're printing CMYK you wouldn't really use a Pantone color anyway. The value of Pantone is that you can get a specific color with just one printing pass. If what you're printing only has black, and forest green, then instead of doing a cyan pass, a magenta pass, a yellow pass, and a black pass, you can do a black pass and a Pantone 17-0230 TCX pass.
