Montage fm is indeed updated although FM hasn't fundamentally changed, it will still be best at percussive stuff like ep's and not so good at strings.

The dx7 was groundbreaking because it was a new synthesis system, really good value, and sounded pretty good on the things it was good at! Also it pushed the other manufacturers to raise their game.

Yamaha funded research into development of a synthesis technique that could be implemented totally digitally because then they could mass produce the stuff cheap. What the got was fm. The first mass exposure to FM sound was ELP Fanfare for the common man, although that monster played by Keith Emerson was built and sold by the Yamaha ordan division and is built mostly using discrete chips rather than the LSI chips used in the dx range.