From the OP's link:
State officials, besieged by requests for more seasonal displays at the state Capitol, have approved several more - including a "Festivus" display honoring a faux holiday popularized by TV comedian Jerry Seinfeld.
There is at least one precedent for the concocting of a fake holiday at the end of the year: the observation of Kwanzaa, an artificial attempt to create an alternative holiday festival to Christmas designed to appeal to African Americans, supposedly based on the notion that Christianity is a "white man's" religion. How patronising, and how ahistoric, given the existence of Christianity in Africa since ancient times. I'm sure our Ethiopian and North African brethren (EO and OO alike) would be quite insulted by this.
Most people now celebrate the holiday on Dec. 23, as depicted on the December 18, 1997, Seinfeld episode "The Strike."
The holiday includes novel practices such as the "Airing of Grievances", in which each person tells everyone else all the ways they have disappointed him or her over the past year.
Interesting mentality. And most un-Orthodox. Compare this "airing of grievances" with what the Orthodox do on Forgiveness Sunday, before the beginning of Great Lent. A world of difference.