Along similar lines, it would be useful to map a speaker's vowels in vowel-space (and likewise for consonants?) to compare native to non-native speakers.
I can't wait until something like this is available for Japanese.
A good accent coach would be able to do much better by identifying exactly how you're pronouncing things differently, telling you what you should be doing in your mouth to change that, and giving you targeted exercises to practice.
Presumably a model that predicts the position of various articulators at every timestamp in a recording could be useful for something similar.
.. unless they had access to a native speaker and/or vocal coach? While an automated Henry Higgins is nifty, it's not something humans haven't been able to do themselves.
Japanese is sort of like this - you have to say foreign words the Japanese way very forcibly, to the point that Americans will think you're being racist if they hear you do it.
Do you have a source for this? It doesn't seem plausible to me, but I'm not an expert.