Regarding the link on my system in /etc lrwxrwxrwx 1 root 39 08-09 02:29 resolv.conf -> ../run/systemd/resolve/stub-resolv.conf ( with body mostly from /lib/systemd/resolv.conf ) that I had to remove manually,
In /var/log/apt/history.log.5.gz I see: Start-Date: 2020-08-09 02:28:50 Purge: resolvconf:amd64 (1.82) End-Date: 2020-08-09 02:29:24 So A HA, that is how it got there.
