PPTP VPN missing in "connection type dialogue" in Ubuntu 16.04

There is no PPTP VPN in network manager connection type dialogue.

Packages pptp-linux network-manager-pptp are installed.

I believe you are missing the GUI components of Network Manager PPTP VPN packages. pptp-linux is the core for PPTP functionality, and network-manager-pptp is the core for Network Manager's PPTP functionality, but the core required software and libraries does not equate to the GUI components which show in the Network Manager GUI.

Install the network-manager-pptp-gnome package and see if it becomes available under VPN items

sudo apt-get install network-manager-pptp-gnome