Can Log In to Legacy Client on NA Server

Hey guys, Zooreka here. I logged on to good ol' League of Leggo for a game today, 4/26/17, and noticed that my new client offered me the option to log in to the legacy client. Since I play on the toasteriest toaster to ever toaster, I had to check this out since my games have suffered a significant FPS problem since switching to the new client. Lo and behold, the link brought me to the legacy client, let me log in to said client, and let me get queued up for a solo duo ranked game. At present, I am now sitting in the lobby picking my champ. Any idea why I was able to do this?

I took a screenshot above of when I was getting queued up for proof. The bottom right hand corner shows the date on my computer.

EDIT: Got an additional screenshot of the homepage.