According to the
Star Trek Encyclopedia (4th ed., vol. 2, p. 509),
"Roddenberry reportedly suggested the second USS Enterprise-A, launched at the end of Star Trek IV
, had previously been named USS Yorktown
since it seemed unlikely that Starfleet could have built a new Enterprise
so quickly. If this was the case, the Yorktown
may have made it safely back to Earth and been repaired and renamed, or perhaps there was a newer, replacement Yorktown
already under construction at the time of the probe crisis." The latter scenario could be supported by dialogue from
Star Trek V where the
Enterprise is described as a "new ship" by
Scotty, whereas the former scenario serves as a convenient rationale for the difficulties Scotty had of getting the apparently recently
refitted ship (therefore also fitting his "new ship" remark, akin to a similar remark
Will Decker had already made on the refit-
Enterprise in
Star Trek: The Motion Picture) back in operational order after the debilitating effects the Whale Probe had inflicted on it.