This is the same terminology that I'm familiar with.
However, I think composers and music editors might differ with your strict usage of the term "stems." In film re-recording, our "stems" are D/M/E which, when mixed together at unity, will yield the final printmaster. In Music Land, they're mixing music only so their "stems" may be drums, synth, strings, etc. which, when mixed together at unity, will yield their intended final mix. Once they deliver their "stems" to the re-recording mixer, some will still call them "stems" while others, like yourself, might call them "premixes." It might be a "bananas/ banawnas" at that point. Of course, in the end they'll be mixed together and comprise the "music stem."