Keeping false hopes is bad ... i agree. But just as bad is to needlessly frustrate them. :-/
Yes, we know that most of PHB should be present (corect me if you have link to their original statement, but i believe they didnt say "all" of it) ... Beyond that? We dont know anything.
And stating both absence, or presence of any other content is nothing but a wild guess. I just cant understand why people cant simply say "we dont know" rather than "nah, this will never be there since its not from PHB" ... Just by looking at the game right now is unshakeable proof that second statement is factualy false.
Most people don't say the former because otherwise, you would have a lot of not so bright people who would endlessly complain about being betrayed. Just look how people reacted to the 2nd birthday, and there wasn't even an announcement there!