First some overoptimistic people thought 100% sure every subclass in Players Handbook will be included
For the record - I don't think we should condone calling "Expecting the company to deliver on the things they said they would" to be 'overly optimistic'.
Anyone who knows about the realities of coding and what is actually in the PHB knew it was overly optimistic (AKA impossible) the instant it was said. Fore those in the know, it was clearly hyperbole. But in the internet age it was an unwise thing to say, as we know that there are people who take everything you say literally, and ignore all attempts to backpedal.