Brian,In 2014 the FAA wrote in the Beard Letter "because this exception [not needing a flight review for solo] applies to student pilots, a pilot who holds a higher level certificate and has an endorsement for solo flight under 61.31(d) must comply with the flight review requirements in 61.56 before acting as pilot in command of any aircraft."

(Link to letter: http://www.faa.gov/about/office_org/...rpretation.pdf)