We know that many older people that are seeking diagnoses and/or self-identifying as Autistic. This issue has had limited attention so far but as the generations of people who now have a clear diagnosis get older, we are realising that very little work has been done on what it means to be autistic and ageing.
National Development team for Inclusion have developed a resource to start conversations about this. They call these conversation starters:

National Development team resource
The National Autistic Society has an article about ageing and loneliness:

National Autistic Society article
The British Psychological Society have also looked at this issue:

British Psychological Society
Autism Europe have created some resources on ageing:

Autism Europe article