[radiowave]

There's a lot from the D-50 that's missing on an MT-32, like 50% of the ROM capacity, and all of the filters and effects.

And on top of that, DigitalNativeDance is an outlier. It was (for its day) such a profligate use of ROM that it's not even representative of what a D-50 could do, in general.

Not that this contradicts your main point about GM constraining the choice of sounds.