How did she know you have several citizenships? 
AFAIK the law does not specifically say that all citizenships have to be renounced (lawmakers havenāt thought about someone having multiple citizenships 
), but that seems to be the interpretation of the MOI.
Government officials have been wrong before e.g. blocking gay marriage for people who canāt legally do this in their home country. Challenging that is long and costly through the court systems.
The renunciation is pointless in many cases as several countries allow to regain it fairly easy. Some regain their other citizenship before naturalization process even starts. lol
Or like Japanese government that does not allow to renounce if you want to do it for the purpose of Taiwanese naturalization.