Which means the fully qualified claim is something like: Musk is the first SNL host[1] with professional diagnosed[2] Asperger's syndrome to be public[3] about it.
[2] Either Musk doesn't know about Aykroyd, or doesn't accept that someone might have Asperger's unless they have been professional diagnosed.
[3] Not everyone is public about all of their illnesses. What are the odds that a previous host has Asperger's but didn't think it was relevant to be public about?