I own a house in a subdivision. A homeowners’ association, created in the 1980s, wants to bring legal action against a neighbour. Could this be a problem for me?

Yes. If your association syndicale libre (ASL) has not updated its bylaws to comply with the law resulting from the 2004 reform (Article 60 of Ordinance No. 2004-632 of 1 July 2004), it retains its legal existence but can no longer take legal action because it has lost its legal capacity.
To regain its rights, the ASL must file compliant bylaws with the prefecture and publish a notice in a legal announcements journal.