That was one potential argument, but if(!) I am wrong about the "faring forth", then I am happy with "little is known" being a "spoiler" to the remnant elf-less march as you described. I admitted that above because that is exactly how I read it in the published work originally (hence the smiley), before I read HoME. But this is a distraction from the elephant in the room IMO.
Which is the summons. IMO the remnant Elves were included in the summons with the Fathers of men, which (in addition to Elrond's eyewitness account in LotR) makes the "little is known" bit nonsensical, unless they chose not to go (apart from Elrond!).
Hope I have clarified rather than adding more confusion!


