In a suit alleging discrimination in employment practices, a material change in the plaintiff's working situation moots a claim of retaliation that seeks injunctive relief where there is only a speculative possibility that the employee might be transferred back to her old position.
http://media.ca8.uscourts.gov/opndir/18/06/172229P.pdf
Since 2011. An occasional commonplacing of the U.S. Circuit Courts of Appeal.
Neither an authoritative statement of the law nor legal advice. Quick work.