He's shockingly naive about forced labor. It's a shame that someone of his stature could claim that slavery "ended."
Furthermore, although there's nothing wrong with AJWS, I question his choice of charity given that there are so many non-profits whose sole goal is the elimination of forced labor.
Slavery exists, but is not culturally accepted the same way as it used to be. De Facto slaves exist, but a legitimate slave trade doesn't any more. You couldn't buy a slave at an above-board auction, bring it home the the US, and then exploit it.
However, women are exploited in lots of the moden world, and laws exist to maintain these practices. Women are kept ignorant by national and religious law. Marriage law often dictates a lower marriagable age for women than for men. There's many areas where women are restricted from education by law.
You couldn't bring a purchased slave back to the US with everyone's knowledge that you'd done so, and have them perform sexual favors and clean your house for you.
You can go to the Philippines and pay to marry a young uneducated woman and bring her home and introduce her to all of your friends. You can have her perform sexual favors and clean your house for you.
It's currently culturally acceptable to do the latter because she's your wife, and we have laws and rules that make that acceptable. If, on the other hand, you were to tell everyone about the new slave you purchased, you wouldn't get any pats on the back, instead you might get federal investigators at your house.
Forced labour still exists, but it exists typically as a criminal and immoral act. It exists in places where authority can't be exercised due to weak or corrupt government. Generally laws exist to prevent it, but those laws can't be upheld.
Discrimination against women exists in the open. Laws are in place which enforce it. It's not just that laws exist that aren't being followed, it's that laws exist that make it impossible to avoid. There are still places where a child bride can try and escape their much senior "husband" and will be caught and by law reunited. While a corrupt justice system might easily turn a blind eye to slavery, there are corrupted laws that say that 14 year old girls can legally be married. Not boys of course, they couldn't afford it at 14 anyways.
The issue isn't that forced labor still exists. Generally even where forced labor exists, it's still at least nominally considered wrong. Murder is generally considered wrong everywhere, it doesn't mean it doesn't happen. But there are still many many places that find the exploitation of women perfectly acceptable if not necessary to maintain a stable society. This is the category that slavery used to be in. Slavery still exists, but is now unacceptable. Discrimination against women exists and is still very much tolerated if not promoted and institutionalized.
Furthermore, although there's nothing wrong with AJWS, I question his choice of charity given that there are so many non-profits whose sole goal is the elimination of forced labor.