friend told me the Operation Cinder references were from Star Wars Battlefront 2, the main plot point of that game was the thing where a group of admirals were carrying out Palpatines last command, "The Contigency", to exterminate a bunch of Imperial planets from orbit upon his unexpected death. As a sort of show to the galaxy that the Empire was needed to keep order, to rally the remaining Imperials in a bond of horror, etc. The Battlefront 2 game starts with the playable character being called by her dad (an Admiral) to begin preparations for Operation Cinder and ends with the Battle of Jakku, which is where TFA begins 4 decades later.
"The Emperor commands it. We will purge this planet and others. Fear shall spread, and the galaxy will remember who is in control."
Pretty damn deep lore cull, its insanely impressive what a breadth and width of Star Wars lore Filoni and the other writers have