Thanks Mang, that was the first thing that crossed my mind and the first thing I tried.
Unfortunately it didn't work as it was originally on Square Enix's end (The certificate seems to have been updated today and I stopped getting these messages; Note, I haven't made any changes to my browsers nor software since Beta Phase 2, this began appearing a few days ago).

Kraggy, no one is trying to scare anyone, calm down.
This was indeed on Square Enix's end and I suspect it's the reason so many people were reporting a "Black Screen" on the launcher (Unable to connect/verify the web server/page the login is hosted on).
I could see the login fields after trying several times. But as noted above, Square Enix has updated this certificate. I am not sure what was causing it since the dates on the certificate seemed "fine" to me, but it is now fixed so...