The problem with those is that for Carth the warning about the Katarn was never intended for Kashyyyk.
Kotor 1 had an E3 Demo much like Kotor 2, and just like how the Kotor 2 Demo contained elements that weren't in the final game the K1 Demo had a few oddities. First off, the game's engine wasn't final so the game looked like this, it was set on Dantooine, you could recruit Carth and T3-M4 (who was owned by Bastila), there was a Sith Base on Dantooine (It possibly reused the cut Czerka Depot), the player was a Jedi who wore Nemo Robes (So the player character Jedi you see throughout the vanilla game were the players in the Demo), and Katarns were the primary enemy on Dantooine.
The Carth quote about the Katarns goes like this: "CARTH: Is your communicator on? It's Carth. Just wanted to remind you to be careful out there. Don't end up as a meal for one of the katarn."
That line exists on TLK number 380, and you'll see that "CARTH" is actually written on that line. The very next line, 381, goes like this: "CARTH: Get back to the base! The Sith have attacked! Just follow the smoke! Hurry!"
So... there isn't much to go off of in terms of restoring the Katarn warning because it was never intended for the actual game. And as for the HK-47 lines about the Sand People Messiah, as far as I'm concerned I've never found, or heard of other modders finding, the cut lines which could be used to restore such a scene. We all most likely know about the Sand People Messiah content through former Bioware devs who worked on the game instead of through cut dialogue lines, so again a mod that adds the Sand People Messiah would have to be costume made.
As an actual discussion forum, perhaps, but there are still mods being worked on, published, and updated by modders and said mods are still being downloaded by players. So the mod hosting element of Deadlystream is still kicking, and the Discord side of the Deadlystream community is thriving, if you think this site is dead that's where everyone went.