Does anyone know if problems with IP could arise if they make a game, let's call it 'Quest of Heros' and then say it is compatible with HeroQuest? The rules may be compatible, but the name is different?
Otherwise, I am not convinced they would get nearly as much support by releasing a similar game that does not have the HeroQuest name. Are there not already many enjoyable dungeon-crawl games out there? What is to stop the thousands of people who had gotten on board to just use those rulesets and tell themselves its a reincarnation of HeroQuest? GZ might be able to pull it off now that they have had so much press about it, and their sculpting quality speaks for itself. However, I think most casual observers would pass once it no longer has the brand recognition of the name 'Heroquest 25th anniversary'
IMO, most people are swayed by the image of a memorable/superior brand. Renaming the game would strip that away and it would be just one of a multitude of options already available.