As far as I know the firmware is done. They just have to set up the servers/redesign the page for the new update. You never know when an earthquake could hit, a fire, hardware failure etc. Thats why you dont ever promise something to someone when youre in a business. "Should" is a vague term but it protects your interest as well as the sellers.
"As far as I know the firmware is done. " But you don't really know, yes?
If it were 100% done, consistent with last time, it would be out as a private beta. Private beta comes before public release.
Thus, it does not look like it is 100% done. It just looks like stalling tactics.