The "Parisien" article says that Dimitrius is "one of the film's villains" (and they really seem to avoid naming him as the main baddie). Stax' report quite clearly says that he's a "supporting heavy", and also that the "main villain" is someone different, who has not explicitly been referred to as "Le Chiffre". But just because a source couldn't tell the main villain's name, this doesn't mean that name will not be "Le Chiffre".
I'm also a bit in doubt about the name "Massus". This can simply be a case of misunderstanding. Someone heard a name that could have sounded like "Massus", which could as well have been "Mathis". Sources don't always get or deliver their information in written form. (Heck, if someone just gets to overhear the name "Vesper Lynd" in a conversation, it could as well be misheard as "West-Berlin" - catch my drift?

No reasons to panic, IMHO.