I used to think a bit of info about their project prior to the demo release was a fair idea, but I'm going to side with the big cheese, after all.
The difference here is that with Recettear, CF had no reputation to lose, while with Chantelise, you do.
I don't think their reputation hangs on telling people about everything they do, 6 months in advance. If anything, that could even be their undoing (well, ok, not really; but it could have negative effects), if the project encounters problems along the way.
Think of it this way: you're slowly feeding your audience, with the risk of their eventually getting the gist of the main dish (or having higher expectations for it) prior to its being served. People may frown if you take your time with preparations, or if it turns out to be less than they'd expected; you're also likely to have people less excited about it, when it finally comes.
People are more likely to remember the moments you screw up, rather than those in which you don't; so I think avoiding negative impressions is a good thing.
I already know what to generally expect from Chantelise, after hearing about their working on it and my subsequent looking into it, out of curiosity. When CF release it, the cake will already look familiar, to me.