This morning I noticed an update to ubuntu-wsl (version 1.361.3) in my updates on Ubuntu 16.04. Specifically What purpose (if any) does this package serve on a standard Ubuntu installation? As it's described as "Utilities for integrating Ubuntu well into the WSL environment" I'm guessing none. All I've been able to find on it is "The ubuntu-wsl metapackage will allow adding new packages for WSL installations only when more integration utilities become available." as mentioned in this bug report but as I'm running standard Ubuntu (Xenial) it seems a useless package for my environment. I don't recall installing it but I guess I must have or I wouldn't be seeing.
Changes for ubuntu-standard versions:
Installed version: 1.361.2
Available version: 1.361.3
In my environment it does nothing as I'm not running WSL and ubuntu-wsl is a meta-package and it's primary purpose is to handle WSL integration.
Here's an excerpt from the control file in the .deb
The changelog within the .deb provides further clues as to why this latest update was pushed out.