I feel you're making this more difficult than it actually is by over thinking it. I offered up a few general opinions and left the discussion open to other forum members and they contributed with their own opinions on the subject. Just say what your initial opinion is. There's no right, wrong, or set rules here.
In my opinion, NA hurt, while 200X helped.
I think if they had continued to produce new cartoons, it would have kept the line going strong. Even if they only made a few new episodes a year just to feature new characters as they came out, it could have done the trick. Instead of ending the He-Man series, they should have produced 13 to 18 new episodes a year for as long as they made He-Man figures to show off the new toys.
NA was a fairly successful toy line that lasted, what, 2-3 years on the shelves? In that sense, it was a success in it's own right, and, since most folks don't even remember it outside the die-hards, I can't see that it had much of an effect on the property as a whole.
MOTU 2002, however, had a major impact with it's failure at retail. The toon never got a following, in large part because Cartoon Network had no interest in promoting it. But the big impact was the Smash Blade Horror, and the resulting problems the line ran into not even six months into its life. This is the main reason we all have the joy of battling the Red Screen of Doom every month for our figures: retailers aren't going to touch anything called MOTU right now without a major media tie-in behind it. Mattel's handling of 2002 (not the line itself, mind you; all reports were that sales were solid until the pegs got filled with funky blue He-Men and Mattel started having problems delivering the product to retailers) damaged the brand, and we can only hope that this new line captures enough attention to wipe away the sour taste of the Smash Blade in retailers mouth...
I enjoy and am happy that both NA and 200x existed. And I have to agree with Scott on what he said above.
It does make you wonder, though. What things might have been like for MOTUC if 200x, and even NA, never existed. How would that effect the line's availabilty. Would there be a new cartoon? A movie? Would the toys be in the stores instead of online?
It's certainly an interesting "What If?"
NA for as much as I didn't enjoy that idea in the least, it barely exists, of all the launches that is the one people have no clue it ever existed so I dont think you can place any blame on it. 2002 is abit better but when I sell them on craigslist the emails I get are completely clueless that a relaunch ever happened. It kinda goes with my philosophy about forget aiming it at kids with the same ole formula as it clearly is not getting the attention in this modern world of electronic toys. Go for a more controversial R rating animation for adult collectors on HBO or something. We could use another BTAS like evolution in toon land.
I don't think either NA or 2002 hurt the franchise, but their effects were very different.
The franchise was damaged in the first place. Pre-Filmation fans would argue that the cartoon caused the damage as it moved MOTU a long way from its origins. But commercially, Filmation did no damage at all - it probably extended the life of the line.
Things come to an end though, and by the time MOTU reached its end, there were over seventy figures, so over-saturation had definitely occurred. By the time the film came out and those last few figures appeared, MOTU had lost its way.
So when NA came along, it was an attempt to revive MOTU. Many felt its inherent fault was that it was completely unrelated to the original concept, and 'going barbarian' would have been a better move. So NA wasn't damaging as such - it was just a new idea that was only moderately successful among a small following. For me, it has no place in the MOTU canon.
2002 was a different story. It had its problems (too many variants and manga styling), but it was an attempt to revisit original ideas, so it had quite a lot of support. There were some good interpretations of the figures, and it certainly has a strong following today. So 2002 didn't damage the franchise either.
As far as their influence on the Classics goes, I think NA will only make a tiny contribution, whereas 2002 will have a stronger impact. That reflects the number of fans. Ultimately though, MOTUC is about bringing MOTU home, so those original ideas will make the biggest contribution of all.