It's kind of true, but it wasn't a slave to the fans, it was a slave to the lack of vision and understanding on the devs' part. They were undoubtedly told by management to copy the supposed "good" parts about 3 and 5 but also stay within confines of 6's ideas and the result was a weird derivative Frankenstein's monster that couldn't stand out on its own and didn't do anything particularly well. Now I know the article isn't actually about that, it's about how 7 was a deliberate attempt at pleasing core fans who didn't like 6. Except the problem with 6 wasn't that it was too innovative, it's that it wasn't very good. Similarly the problem with 7 isn't that it's stale, it's that it also isn't very good.
The article does have a point - why make a new game when it doesn't offer anything meaningfully new? It's a conundrum even NWC ran into after the third game. This isn't the only franchise to suffer(?) from this. People who love Worms 2 don't need 20 new Worms games, they just want Worms 2, possible refined and improved. It's the same with Age of Empires 2, the game did what it did so well that simply repeating it and calling it AoE 3 won't work very well.
Could a product that's like Heroes 3 but better work? Yes, but it would have to be actually BETTER. It would have to refine the very, very few drawbacks Heroes 3 had. It would have to deliver a huge amount of content and it would need a perfect understanding of what made the design work so well which nobody at Ubi or Limbic had. Ironically the best approach for Ubi would be to do something like Age of Empires II - take the source code, refine and expand. We all know what they made of that opportunity.
Ubi wanted to coast on a brand name with built-in playerbase and didn't want to do enough work, but also didn't know how to break new ground. Well, they did, they made a few mobile games for China. Thanks for that, Yves.