I did a little research, and by that I mean I did one search in Wikipedia, and it seems obvious that no American holiday is ever discontinued. Each outdated holiday is supplanted by another holiday.
We initially celebrated Armistice Day/ Remembrance Day on 11/11 with the rest of the world, probably even handed out poppies, but then in 1954 we were glad to embrace ALL the wars and rename it Veterans Day.
Then they took Decoration Day and called it Memorial Day, so that the North and South decoration days for all the civil war dead could unite. (Worse, they changed the date in 1970, which still messes me up to this day.)
There seems to be a courtesy delay of 50 years before messing with a holiday. So, what’s the plan for repurposing Pearl Harbor Day? It seems every few years the current President — Clinton, Bush, Obama — re-declares it a National Remembrance Day. It’s hobbling along.
I would hate to think of it, but might it someday be united with September 11 to become a day in which we remember days when we were attacked. Attack Day? Homefront Day?