There's a rock and a hard place situation here: TSCC is all based on the "restored gospel", with its attendant First Vision and all the crap goes with it, so they are tied to these important dates because that's one of the first things the missionaries talk about to investigators. Unfortunately, there are many dates (as pointed out in the article and comments) that *were* important, but now simply embarrassing....
If you asked a Lutheran what date Luther nailed his 95 Thesis to the door or an Anglican what day Henry VIII told the pope to stick it because he was going to get a divorce, they wouldn't know or care.
The Lutherans would have a hard time forgetting the date when Luther nailed his 95 Theses to the door, as 2017 is the 500th anniversary of the Reformation and the celebrations are going on for a while including special Reformation printings of the The Lutheran Study Bible, commemorative coins, etc..
As for Henry VIII, I don't know...but he was only a King...:-)