That's what the grimoire and story missions heavily hint at. That's why the House of Kings are so desperate to get to the Traveller, resulting in the Battle of Twilight Gap. The insult that Taniks, notably Silent Fang and basically every Fallen enemy says, "She'lot", I figure, translates to "Thief of Blessing", or "Light Thief", ESPECIALLY as a contrast to Taniks' Strike name, "Shadow Thief". As "Sha" was translated from Skolas to mean "Gift (of)", I speculated that "She" could mean the literal opposite, "Theft", but change it into more of a noun that could be applied to someone. This opposite "a" and "e" sound I believe could be a pattern, for example: "drass" (before) and "dress" (soon). As for "Lot", that's pure speculation. Variks goes on about the Great Machine, Blessing and Whirlwind, so I supposed that if the Fallen were to believe any of those three "belonged" to them, it would have been the Blessing, or "Light", which sounds a lot like "Lot", yeeeeeesss?

Yes, they called it the Great Machine.