For me it wants to remove the open connect client, which I need to vpn to work.
The following packages will be REMOVED:
network-manager-openconnect network-manager-openconnect-gnome
The following packages have been kept back:
lightdm-gtk-greeter ppp
The following packages will be upgraded:
libpython3.4-minimal libpython3.4-stdlib python3.4 python3.4-minimal
4 upgraded, 0 newly installed, 2 to remove and 2 not upgraded.
Doing what ayla suggested, marking the packages to be removed on hold and then doing a d-u works, but ppp which is the culprit wanting to remove network-manager is not updated.