Consider that the Witness can also resurrect the dead, and his forces are capturing humans, most likely for expiration. So it's possible we could see Amanda return not as a guardian but as a Disciple. This would have huge story implications and cause major emotional impact on several characters. Not to mention, the heaviness in the air of the pyramids may actually be the Witness corrupting them just like what happened to Uldren or the techians back in forsaken It's a long shot bungie would take this route, but I sort of hope they do. It would definitely be more interesting than Amanda becoming a guardian and Crow killing Eramis to get revenge, then Eramis becoming the 1st Eliksne lightbearer.