Briefly, tell me what they said about the old universe!
In general, their words about "respect" for the old universe are a big farce. If they had the respect they talk about, Erwan Le Breton and Richard Dansky wouldn't be rambling in the Heroes 5 developer diaries about how they are "creating a new universe with maidens and gambling." And they wouldn't try to say that there was supposedly a "weak connection" before, while in the next sentence demonstrating their lack of knowledge about the lore of the NWC universe. And they would definitely have preserved the old universe. Tim Lang, one of the developers of MM 6-8 and the lead designer of the ninth game, after the collapse of 3DO, worked for some time at Nival and even wrote drafts of the plot for the tenth part. Nothing prevented them from creating Ashan, but not abandoning the old world (at least for the original RPG series Might and Magic), developing them in parallel. For further work on the old universe, they could have invited John Van Caneghem and/or Ron Bolinger, the actual authors of the universe, or someone else from the former NWC writing team.
We should thank Julien "Marzhin" Pirou, a well-known fan of MM and currently a member of the Heroes 6 development team, for adding the aforementioned parallels with the old universe.