Yes, I think in my own opinion a disabled person can make money on fiverr probably let's take for example a blind person can have one of his relatives create a gig for him on her on a niche on fiverr named 'I will keep your company on a call' All this blind needs to do is just to keep the conversation going and talking to the person that places order. So indirectly, fiverr has provided both of them a great satisfaction whereby the blind person gets to be active and the buyer that ordered the gig gets to kill boredom during the conversation.
In summary, I would say fiverr gives room for a disabled person to work.