What I suspected happened: after playing the demo, fans completely changed their opinion about Heroes 5 (for the better), and I no longer see any reason to fear that "Heroes is dead."
So, we can calmly spend our time playing Heroes 3 or the demo of Heroes 5 (for those who have it; I don't have the opportunity to download it due to my terrible internet connection) until the release of the main domestic project in history.
P.S. Can anyone tell me the release date for Heroes 5? Different sources are giving different information.