In revised editions
Note On The Shire Records states that though Elrond had departed his sons
'... long remained, together with some of the High-elven folk.'
I think that Foster's entry is not simply based on the sons not sailing with Elrond however, but arguably Elrond's and Aragorn's words from the Tale of Aragorn and Arwen:
'That so long as I abide here, she shall live with the youth of the Eldar (...) And when I depart, she shall go with me, if she so chooses.' Aragorn responds that the years of Elrond's abiding run short at last,
'... and the choice must soon be laid on your children, to part either with you or with Middle-earth'. Elrond answers 'Truly' but notes
'soon as we account the years'. Earlier in the N. Kings it is also noted that the children of Elrond had the choice to pass
'...with him from the Circles of the World; or if they remained to become mortal and die in Middle-earth.'
Of course the option remains that 'with him' means 'as he did' or similar, but especially the conversation with Aragorn seems very much about timing to my mind. There's an interesting draft text called
T4 in The Peoples of Middle-Earth, which according to Christopher Tolkien:
'...was and remained for a long time the form of the Tale of Years that my father thought appropriate, and was indeed proposed to the publishers in 1954.' It reads in part (concerning Elrond's children):
2300 '(...) These children were three parts Elven-race, but the doom spoken at their birth was that they should live even as Elves so long as their father remained in Middle-earth; but if he departed they should have then the choice either to pass over the Sea with him, or to become mortal, if they remained behind.'
Again, I realize one can work around this, but taken all together (not that Foster had this last bit to work with) Tolkien has (IMO) at least left the impression that to stay in Middle-earth when Elrond departed reflects the choice of mortality. Of course letter 153 often pops up, that they delayed their choice. Not that I toss out letters (sent or not), but
The Lord of the Rings is a different animal, and the text is, in some sense at least, 'later' than the letter. Perhaps people disagree that there is the suggestion that they chose mortality here, but...
... RF used 'seem' at least
