I’ve heard that African countries are less likely to get things like this because so many of them are “connected” via assorted means. These shirts, etc. are more likely to go to places like the Andes or Papua New Guinea, where people may not know, or care, what the items say or mean.
Other ideas for outdated but still-wearable clothing: Community theater, and crafters; some quilters covet polyester double-knit because it’s so sturdy but very hard to find nowadays, and I have a friend who makes stuffed animals for charity and stuffs them with old clothes, so they’re 100% machine washable.