Zondervan did not always publish the Scrivener edition, and may only be reproducing it in some of its KJBs.
As for the one mentioned by textusreceptusonly, it is probably following one of these two editions: The two edition-types from recent years with lowercase "spirit" in Genesis 1:2 are the Cambridge Standard Text Edition (appeared in circa 1993), and the Eyre and Spottiswoode Edition from about the 1950s.
The American editions traditionally (but not always) followed the Oxford or a mixture of the Cambridge Edition(s). These type of KJBs (as were printed by Thomas Nelson and others) were considered "normal".
Two things have happened in recent years:
(1.) a lot of editing/modernising has been going on in KJBs.
(2.) there is now a rising degree of understanding concerning the editions issue, including a push to promote one particular Cambridge Edition as the standard edition.
See
http://www.bibleprotector.com/purecambridgeedition.htm