I think he's assuming that the game will be highly compatible with d20M, as Pathfinder was with 3.5.
In which case, they would certainly have a huge head start in the form of the MSRD.
However, that hasn't been my impression, it sounds like they're reinventing the wheel, which is where I lose interest I think.
I'd actually welcome reinventing the classes a bit. I've played d20 modern extensively, I've played your Modern20, and I've dabbled in Spycraft and Star Wars Saga.
I like a lot of what you've done with Modern20, but I've met with some pushback from the players on the hit location system (we've moved to only checking on potential injuries), and the skill ranks granting abilities (they say it reduces the importants of stats, and would prefer the benefits to be feat-driven). So it's not our perfect game (though we're still running it, house-ruled.
The problem with existing d20 Modern is this: the class system is open ended. The classes in the book, like 3E, are not intended to represent every possible archetype. The assumption is that a character will take an Advanced Class to specialize, but the number of Advanced Classes out there is rather small. I suspect that they intended on elaborating further on the system, but the success was lacking.
There are, of course, other sources of Advanced Classes, such as the Game Mechanics books, but the system has a sort of dissonance. On one hand the stat-based classes imply the ability to construct any archetype you want through combinations of classes, but then the Advanced Classes represent a different and better way to portray most archetypes, so there's no need to dabble in half tough/half dedicated, for example. The only place that would come in is at high levels, but those are unlikely to be reached.
Also, many of the Advanced Classes in the Game Mechanics books seem to have a slightly different design philosophy (they're less broad in the archetype they cover), and there are some rules issues you've got to be aware of when incorporating them into your game.
SAGA, on the other hand, is a beautiful system, and I'd like to see a class system similar to it. Perhaps 6 classes with extensive talent trees that contain the major abilities of the current advanced classes. That would, I think, be a much more elegant system.
From what I've seen it also appears to be the route P20 Modern is going, which interests me greatly.