Though there might be different types of victories—peaceful victory, victory by sacrifice, even a truce—Sith dogma taught that unless the victory was achieved by demonstrating that one's power was superior it was not true victory.
The Sith desired to free themselves in order to reach perfection and fulfill their potential.
No doubt this new symbol is a much more distinct and memorable re-invention of the Sith insignia - one that works in perfect coordination with the angelic wing look of the Jedi symbol, which similarly invokes the three-pronged symbolism if The Father, Son, and Daughter.
Star Wars creator, George Lucas, took the Gaelic word Sith meaning fairy or sprite.