Intentional false advertising? I think not. Someone just forgot to add the part stating "if you have purchased HD".

People are human, they make mistakes, others need to understand this and stop making them follow everything they said to the letter.

Besides, Kate - it seems - isn't there anymore (no official word, so who knows), so anything she may have said may possibly no longer hold value.

Although saying something repetitively, like "Epic Quests will always be free to all players" and then changing it, is a completely different story.