It has limitations in the sense that calculated or measured colour, expressed by two numbers, x and y, is instead represented by a single number, temperature. It is possible for different pairs of x, y values, i.e. different colours, to correspond to the same CCT.
Even so, I used to work in lighting and have performed x, y calculations in the past for LEDs based on measured spectra, rather than datasheets. I then measured the resulting chromaticity. For various combinations of LEDs (e.g. whites plus ambers) I tended to find good agreement between prediction and measurement for my prototype lighting fixtures 😉
It’s a straight forward calculation to do with a short computer program and I would invite somebody (not me) to do it for a representative white LED to confirm where it would be located in terms of x and y, and how this location compares to the locus for a blackbody.