The only time they told this was on AC13 press event and that too was a very dicey answer with the game still in bug fixing and at last stages. IIRC they never really said the exact date till you asked them yourself, right?
I asked them straight out. The transcript is available. If the CEO says the game is on time there's not much you can do but wait and see what happens come June 21st.
As for Chief going missing there haven't exactly been a lot of questions recently that haven't been answered already. I'll assume he's working hard to ensure they hit the release date.