If Windows Live Messenger is discontinued, why did it install on my computer as part of “Windows Essentials”

I had a recent hard drive failure and had to replace it.  I did NOT have an image of my old drive.  Rather, I had back-ups of all of the important files on my computer.  This way, I could re-install Windows 7 (Home Premium - 64-bit) from "scratch" and configure it like a brand new computer.   Then, after this was done, I ran Windows Update repeatedly until all updates were installed & it completely was up-to-date.

In order to get Windows Live Essentials re-installed, I followed this path:  Start > Getting Started > Get Windows Live Essentials.  That took me to this website:  http://windows.microsoft.com/en-us/windows-live/essentials

Note that the items listed are:  Photo Gallery, Movie Maker, Windows Live Writer, Windows Live Mail & One Drive.  And, if you click the "Other download options" link, you will see these programs (along with Family Safety) listed as being "what's included" in Windows Essentials 2012.

http://windows.microsoft.com/en-us/windows-live/download-windows-essentials#wetabs=we2012

Windows Live Messenger is not listed anywhere.  In fact, it's not even listed as being part of the old 2009 version of Live Essentials for XP.  That makes perfect sense - the program has been discontinued/retired, right?

So, my questions are:

1) Why, when I clicked the "Download" button and installed "Windows Essentials 2012", did I also get Windows Live Messenger?  Why would Microsoft continue to distribute a discontinued application?

2) Is Windows Live Messenger truly discontinued?

3) What would happen if I logged into it?

Thank you.