That is a convincing explanation.

I have a question about the timeline:
On 31 July 2008, the Navy requested that the procurement of additional Zumwalts be stopped, and that construction of the Arleigh Burke class (Flight IIA Restart variant) be restarted instead.

I found that development of the SPY-6 radar began in June 2009, and that the decision to develop the Flight III variant was made in 2009/10.

That would be AFTER the Zumwalt class was restricted to two and then three ships (which caused a cost explosion also for the SPY-3 and SPY-4).

The first SPQ-9B for an Arleigh Burke class destroyer was possibly ordered in November 2013.