You see this kind of things in design guides quite often*. It just makes little sense to specify RGB or CMYK values without mentioning what profile one is talking about**.
Now theres little point in doing this selection if you select the color a system tells you. Rather you should manually and visually pick one that looks good and fits your eyes best (On a appropriate medium). Then your documenting a well reasoned alternative that has no gamut clash.
See the spaces can not all produce same color, your design intent may not nesseserily be exact match but best possible vibrancy etc. So if you really provide good service thats what you design, presumably your better than my computer. If not then dont bother I am perfectly capable of converting these values myself. Just please dont mislead those that dont know.
So yes the difference is in different color management settings/converion intent. Document those.
* In personal experience i have extensively used 6 different style guides for different orgs and they all had these.
** But only one had a mention of what profile should be used for cmyk printing. But no mention of the RGB profile. Turs out half of all documents were prepared in adobe RGB and half in sRGB. So much for color consistency.
