This also all happened in 1999, right before the LA Times articles in 2000. This was a KRS-1 publicity project that didn't end up working.
BTW, it's a straw man to pretend that this story being a fabrication means that the man himself was fabricated. I'm sure some retired white guy after having a stroke went to a rap open mic battle, got noticed by KRS-1 who thought he might be able to use him, which gave him the social capital to attend events regularly and make friends. I also don't doubt that once or twice during the period of his "rap lessons," KRS-1 trained him like a parrot to have a good minute on stage. Especially with the novelty, I'm sure people gave him a break, and there's no indication he wasn't trying hard, and people like when you try hard.
Those lyrics are horrific, though. Also, shit features like this remind me that if the media wasn't 24-hour Trump, it still wouldn't be covering anything important, it would just have to find 10x more stories about waterskiing dogs and rapping grandpas.