Yes, Christopher Tolkien's discussion in XII is not completely clear. He says among other things that:
Quote:
In the last of the genealogical tables Artanaro (Rodnor) called Gil-Galad appears
|
Thus implementing the note of August 1965. The date of this 'last of the genealogical tables' is not clear, but CT says that these genealogies were still being used and altered when the excursus from the 'Shibboleth of Feanor' was written. This would suggest that the use of 'Rodnor' on the genealogical table was contemporary with the use of 'Ereinion' in the text, in which case the question of which came later is very doubtful.
However, he also notes that some corrections were not made to the genealogy - e.g. the genealogy still has the earlier three daughters of Finwe and Indis whereas in the 'Shibboleth' text they had two daughters. So it seems that the 'Shibboleth' excursus represents, at least in some respects, later ideas than the genealogical table.
Nonetheless, CT, after giving a brief schematic of the final situation arrived at in the table, remarks:
Quote:
There can be no doubt that this was my father's last word on the subject
|
But I think that what he is referring to here is not Gil-Galad's name but his
parentage. That is, the last word on Gil-Galad's parentage is that he was Orodreth's son. He certainly does not offer any evidence that the name 'Ereinion' in the 'Shibboleth' was superceded by the name 'Rodnor' in the genealogical table.