I just read in LWN about the implementation of systemd in Debian ( https://lwn.net/Articles/657345/ ). Near the end of the article was this sentence:
Another upcoming change is support for networkd, a lean interface for bringing up and taking down network interfaces. Pitt noted that there have been a lot of questions about whether networkd is meant to replace NetworkManager. It is not, he explained; rather, it is akin to ifupdown in its scope.
Do you know if "networkd" incorporates any changes from your "ifupdown2" package?