Dior the Half-Elven: Gift of Men or Fate of Elves

[Galin]

In a relatively late text Tolkien wrote:

'Dior their son, it is said, spoke both tongues: his father's, and his mother's, the Sindarin of Doriath. For he said: 'I am the first of the Peredhil (Half-elven); but I am also the heir of King Elwe, the Eluchil.'

The Peoples of Middle-earth, The Problem of Ros, 1968 or later

So Dior is Half-elven, but this is a blood distinction; and he died before the matter of Earendil and Elwing had been considered, with special dispensation given to these beings and their sons.

According to the Silmarillion of the 1930s:

'... all those who have the blood of mortal Men, in whatever part, great or small, are mortal, unless other doom be granted to them.'

JRRT, Quenta Silmarillion, mid to later 1930s

Did Tolkien intend this to be the case in the 1950s and beyond? I'm not sure the answer can be known, but this statement was not used by Christopher Tolkien in the 1977 constructed Silmarillion in any case.

If it was still held to be true however, then Dior would be mortal-fated in any case. If not, he still died before the choice was ever considered and granted for Earendil, Elwing, Elrond and Elros (and if this was special dispensation for the actions of Earendil and Elwing, then in my opinion others with mixed blood need not necessarily be granted the choice).

And again, if the statement from Quenta Silmarillion was supposed to be true with respect to the 1950s and 1960s, then it might help explain why the choice was extended to Elrond's children -- as, if it was not extended, they would still have a measure of mortal blood and thus [seemingly] be automatically mortal and automatically sundered in fate from their parents.

Not extending the choice to the children of a 'mortal chooser' [Elros] however, returns things to the 'natural state' -- all those with any measure of mortal blood are mortal-fated, and children and parents receive the same fate upon death.

In my opinion