IMO there couldn’t be a vacancy in an agency that is newly created and never had an agency head.
What Constitutes a Vacancy?
Historically, questions have arisen about the meaning of the constitutional phrase Vacancies that may happen during the Recess of the Senate. Does happen mean exist or occur?
The first meaning would allow the President to make recess appointments to any position that became vacant prior to the recess and continued to be vacant during the recess, as well as positions that became vacant during the recess.
The second meaning would allow recess appointments only to positions that became vacant during the recess. Although this question was a source of controversy in the early 19th century, Attorneys General and courts have now long supported the first, broader interpretation of the phrase.
An even better reply. Thanks!