Is an A record necessary for a domain after pointing my hosting DNS nameservers to the domain?
Yes, an A record is typically necessary after pointing your hosting DNS nameservers to your domain. When you update your domain's nameservers to point to your hosting provider, the nameservers will direct traffic to your hosting server. However, the A record is what specifies the IP address of your hosting server to which the domain should point.
The A record is essential because it translates your domain name (e.g., example.com) into the corresponding IP address (e.g., 123.456.789.123). Without the A record, the DNS resolver wouldn't know where to send the requests for your domain.