To make the VM images work out of the box, they should default to DHCP (and IPv6 autoconfiguration). People are either going to try them in a VM that does DHCP or one that doesn't. If it does DHCP, then they now don't need to manually configure the network. If it doesn't, then they're going to need manual autoconfiguration irrespective of whether the VM tries to use DHCP.
Ping?
A commit references this bug: Author: gjb Date: Thu May 25 12:53:49 UTC 2017 New revision: 318872 URL: https://svnweb.freebsd.org/changeset/base/318872 Log: Enable DHCP and IPv6 autoconfig on non-cloud VM images. PR: 203653 MFC after: 3 days Sponsored by: The FreeBSD Foundation Changes: head/release/tools/vmimage.subr
A commit references this bug: Author: gjb Date: Sun May 28 03:59:34 UTC 2017 New revision: 319032 URL: https://svnweb.freebsd.org/changeset/base/319032 Log: MFC r318872: Enable DHCP and IPv6 autoconfig on non-cloud VM images. PR: 203653 Sponsored by: The FreeBSD Foundation Changes: _U stable/10/ stable/10/release/tools/vmimage.subr _U stable/11/ stable/11/release/tools/vmimage.subr