Assuming the return to flight is delayed that long I'd have thought they'll have to slow / stop production soon with all the added cost implications.
They would be very foolish to stop production.
These are firm orders and it is strictly cash on delivery. Running out of space is not an issue. The US is very big and space can be found. I'm sure FAA exemption can be gained to fly the new aircraft out to a temporary location without an APU battery. It may even pay Boeing/Thales to set up a remote facility at this location to install/rewire the approved new battery/charging system when it is finally certified.
SoS