I'm pretty convinced they haven't been mining much at all now. They may have just started in the last 24-48 hours.
There's not any other credible reason to delay releasing the address.
Or they've had very bad luck. That's likely the reason for all the delays about posting the address. They're embarrassed about how few blocks they've found (likely zero)
Not likely. The Wednesday deadline was announced by labcoin himself when he could just keep silent. Why he was over optimistic after so many delay happened already. He could just say 'next week' than explicitly 'before Wednesday'.