Videos on Facebook, aka the world's largest social media site with over 1,000,000,000 users, go viral all the time.
And? That doesn't guarantee a video of a 6+ years old song being performed is going to go "viral". The ****? Don't be so bothered that you try and undermine what's happened.
Gaga did it w/ her TSOM tribute tho. Like everyone else has said, these views really only reflect the video's total reach, not the people who actually sit and watch it. It's still a good achievement, but those comparing it to Bad Blood are foolish.