I'm running Wireguard on a number of Debian 9 and CentOS 7.6 VMs. On the
CentOS VMs I experience the same issue as
https://lists.zx2c4.com/pipermail/wireguard/2018-July/003134.html. I'm
using wireguard-dkms and wireguard-tools from
https://copr-be.cloud.fedoraproject.org/results/jdoss/wireguard/ and
using the wg-quick service.

I do *not* have NetworkManager installed.

Each time wg0 comes up, a different IPv6 link-local address is added to
it. With SaveConfig set to true, these accumulate indefinitely.

Using identical configuration on the Debian 9 VMs, I don't ever get any
link-local addresses assigned to wg0.

Xand