It’s always been called the polar vortex by meteorologists (of which I am one)...it’s just that now the media has found the term out and wants to use it because it sounds cooler (lol)...and scarier. I’ve been using the term for 30 years and others before me for much longer than that. It’s not a new term. It’s just new to you and many others.
And I should add that it is a fairly recent discovery in meteorology. It wasn't really "discovered" until the 50's and high altitude radiosonde obs. The vortex sits so high up in the atmosphere that nobody knew about it until we started measuring that part of the atmosphere. Of course, it's always been there and IS in fact responsible for arctic outbreaks in the lower 48. Before the days of advance computer modeling, it was VERY IMPORTANT to know what the polar vortex was doing...because shifts in it can telegraph arctic outbreak weeks in advance. There are many old school rules of thumb that give a heads up that a major arctic shot is coming...and some of them deal with this.
Just think of the media's use of it as a shiny new toy. They'll lose interest eventually and move on...