We had a court order for visitation and joint custody but he only saw he a couple of times after that. Hasn't had any contact for the past 8 1/2 years and is now seeking visitation.

Yes he may, many men often have changes in their life and realise they have done wrong and try to correct those mistakes.

Abandonment is a state law issue and varies ( greatly) by state, In GA it is not paying court ordered child support.

Normally his not seeing the child for years does not take away his rights, you may go back to court to modify any court ordered visits. But if there was a previous court ordered visit plan, if nothing has been done to change it, it is still valid, his non use of it has no effect unless you wish to fight it in court.