Cleon
Hero
Without even checking the Hollow World set, I know the answer to both of those questions is "yes".
In my current working copy I have 2676 lines marked as new additions since the December 2008 release, so that version is most certainly rather out of date. Then, there are three year's worth of 4e releases still in my queue for adding to the index, plus a number of obscure sources I've picked up since 2008 that also need checking, so there is plenty of updating work that needs to be done too. (I've been a bit distracted by the Collector's Guide series for a while!)
If you do spot any omissions, free free to note them in this thread and I'll make sure they get included in a future update. I'm not near my collection right now, so can't immediately check the Hollow World set, but I will make sure I double check the creatures you've mentioned, to make sure they don't get overlooked!
Okie-Dokey.
Comparing the Hollow World Campaign Set to the copy of your index I've got (which appears to be dated 29th December 2008), the index has all of the character races in the Player's Book and all the monsters in the Adventure Book appendix.
It is missing all the monsters from the actual adventures in the Adventure Book, though. Namely...
Sun-Wight (page 4)
Olgaf the Huge, a "Dwarf Giant" (page 13)
Undead Tlachtli Players (page 14)
Were-Sabretooth (page 14)
Frost-Zombies (page 16)
Bounders (page 17)
I'm not sure Olgaf the Huge is worth bothering with, but the rest of them are.
There are assuredly lots and lots of obscure monsters in various AD&D and BECMI adventures. We've started converting some of the Haunted creatures from OA2 - Night of the Seven Swords and there are at least a dozen new monsters in that adventure alone, although a lot of them are merely one-line entries.