This is not about the colors, FYI. This is about someone referencing a specific Pantone product as a spot color. And the automatic conversion from that spot color name to the regular RGB / CMYK color values is now gone. But if you embedded the actual RGB/CMYK values into your file, then it'll still open just fine and display those colors just fine.

Edit: Also, converting from Pantone to regular RGB/CMYK is a lot more lossy than one would think. If I reference a Pantone product, that pretty much covers all properties of the printed surface, including things like reflectivity angles, fluorescence and phosphorescence. A cheap xRite will already measure reflectivity in 13 wavelength bands. And then it'll average those 13 characteristics into 3 RGB numbers. Professional color measurement tools can have hundreds of properties per ink type, thereby making reduction to 3 values even more lossy.

If I give you RGB, that merely specifies the color at direct reflection under normal light. If I give you a Pantone ID, you also now how it'll look from the side or under UV light. RGB specifies an averaged wavelength mixture, Pantone specifies a chemical ink mixture.

Edit2: You know these car paints that have fresnel reflections, meaning they appear to have a different color of you look at them from a different angle? That's an excellent example of a case where you need to specify a specific ink type like Pantone, because the RGB value changes based on the viewing angle.