So following previous suggestions, I submitted another in-game request for codex entries to be granted. I got an email response:
I am Protocol Droid M0-T0, Human Cyborg Relations.
Thank you for contacting us regarding your issues with the Codex.
We are aware that there are issues with certain Codex entries not being granted when the player is eligible. Unfortunately, in this instance I am unable to grant the specific entries you have mentioned to your character.
Damion Schubert (Principal Lead Systems Designer) responded to a question about the Codex in one of our Community Q&As. He stated: "The Codex will get a clean-up pass in the not-too-distant future, and at that time, we'll be either removing the entries that are no longer obtainable or re-enabling some of those removed entries if it makes sense to do so."
The full Q&A can be found here: http://www.swtor.com/blog/community-qa-july-13th-2012
Thank you for your patience and understanding, and we would like to apologize for any inconvenience or frustration this may cause. Should you require further assistance with this or any other issue, please do not hesitate to contact us again.
Galactic Support is our specialty...
Protocol Droid M0-T0
Star Wars ™: The Old Republic™ Customer Service
WOW. Just WOW. They reference a 9-month old thread, with the quote "not-too-distant-future." No changes were made to my codex.
Interpretation is left to the reader.