Michael Jordan was popular in the early 90's. The Simpsons were popular in the early 90's. Put 2 and 2 together to create a shirt kids would beg their parents to buy for them at the local swap meet. I don't think any negative racial connotations were supposed to be conveyed by this.
I remember I had a "Black" Bart as Magic Johnson shirt back then and wore it to Catholic school for free-dress day. No one gave me shit - maybe it was because I was a kid or the nuns didn't know any better. And this was a school that outlawed POGS. Anyway, it was $4.99 well spent
first glance before reading any of the print on the shirt it sort of looks like bart was dipped in chocolate and there's a ball stuck to his hand. and he's also sticking his tongue out because there's a ball stuck to his hand, like he doesn't like it or something.