As much as I wanted to see his LFBC, children do not lose their citizenship even if the parents change. If he was born a citizen he would have to officially renounce at age 18 or after to lose it. One wonders if he enrolled as a “foreign aid” student though. Not necessarily. Consider this case.
Perez v. Brownell
http://www.law.cornell.edu/supct/html/historics/USSC_CR_0356_0044_ZD1.html
Sometimes a parent can put a child into a situation where they lose their citizenship. Perez lost his.