Upgrading your existing Windows 10 Bash from Ubuntu 14.04 LTS to 16.04 LTS)
At this moment, you will need to:
Switch to Windows 10 Preview Fast Ring
Run the following command: sudo do-release-upgrade
After the upgrade, you will need to re-add NodeJS and any other 3rd party repos that you had added. This means repeating steps 3.1 to 3.4 in NodeJS on Windows 10 Bash.