Meh. Most clothing lines are manufactured outside of the US these days, from Africa to Asia. Seems like one of those "gotcha" attempts. Beside, fashion is perhaps the most useless part of capitalism.
It's hypocrisy at its finest. While Trump is certainly not the only hypocritical politician he has also made it a point to chastise several companies rather publically in the last six months alone for sending jobs to other countries or for having their product built in other countries and ran on a platform that highlighted buying American, so the point made in the OP is quite valid. I welcome Trump's chastisement of Ivanka for having her products made out of country, similar to his chastisement of other companies he has made.