The apt-get version of node is incredibly old, and installing a new copy is a bit of a runaround.
So here's how you can use NVM to quickly get a fresh copy of Node on your new Bash on Windows install
$ touch ~/.bashrc
$ curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.33.6/install.sh | bash
// restart bash
$ nvm install node