Future expansions.

They also have a higher priority than the Nagas. But Ubisoft has its own priorities.

Of course, they do. But that doesn't mean they are completely different. Demons, Undead, and Humans were included from the start, not in the expansions.

Based on what metrics? Ubisoft said that there would be no dragons in the game for the Factions, only bosses. But they didn't say anything about expansions, I must note. So, Dragons of Chaos could easily be included, especially since it's such a classic, and they wouldn't just abandon it.

They wouldn't allow that. Compare the Dark Dragon to any champion from any Faction (in terms of the number of squares they occupy). If they introduce a dragon, it will be a small one. A regular dragon won't be able to shrink as much as Kirins do.

And who said they would release expansions in chronological order? Maybe they want to start from the end?

That would be nonsense. And it wouldn't be in the spirit of Heroes 6 (not Heroes in general, but specifically the sixth installment). And how do you imagine that? First expansion: Railagh is defeated by Demons in the Dungeon and imprisoned in Shi'o. Second expansion: Railagh emerges to fight the Angels. Is that what you're suggesting?

In this case, the dragon icons match the icons of the Factions they support. It's no coincidence that Silat, who is "forever alone," doesn't have an icon in the picture.

That's what I meant! But don't you think it would be silly to have a Faction icon with a dragon (that isn't in the Faction's combat ranks)? The icons for the Dwarves and Elves will be different! I'm 99.999999% sure of it.
P.S.: In any case, my vision of the expansions is closer to reality than the vision you get by combining all your answers to the quotes from my post. And this doesn't depend on your popularity on the site, or how much and how you play Heroes.