Yes
Elrond did not mean *Elf of the Cave according to later text (later than this letter). Sometimes I use 'seem' even though I'm really more sure than this might indicate. Anyway, I'm interested in the following question here (concerning the letter I quoted above):
Do people agree that the suggestion in the letter is that the 'infants' were left by the sons of Feanor just after they were carried off, to be found again by someone, and in this scenario would not have been fostered?
That's how I read it, but I've already stumbled across an interpretation that the two were left at the time when Maedros and Maglor finally stole the Silmarils... which seems off to me, despite 'last act' above.
