All the Talking Deathclaws were hunted down and killed by the Enclave; There are none left.
You don't know your lore.
What you speak of was simply an off the cuff comment made by someone who had no creative control over this particular story. The only valid source of information is Fallout 2, and according to that game, a few talking Deathclaws are just fine (including Goris, as you should be aware).
Furthermore, the person who was responsible for designing the talking Deathclaw, and thus the person with creative control over that storyline, has informed us that the talking Deathclaw do have a way to pass on their intelligence to other Deathclaw. So a continuation of their race would be very likely.
In fact, with the destruction of the oil rig, and the Enclave being reduced to simple remnants, the continuation of the Deathclaw race is incredibly likely. As I've detailed with reasoning in prior posts.
And as I've gone to lengths to point out: Life is an adaptive, versatile, resilient thing. Given a high enough quotient of resourcefulness, life would find a way. And Goris always struck me as a very resourceful person indeed. Especially given how he found a way to mingle among humans without them ever realising his true nature.
So please, if we're going to talk about these things, could we stick to purely
canon lore? Thank you for understanding.
(Edited: Just FYI, the Fallout Bible isn't canon. It's just off-record comments made about the game, but it's not actually considered to be canon information and/or lore, it was never meant to be. The Fallout Bible is about as 'canon' as Van Buren.)
(Edit #2: If you want another example of how the Fallout Bible is non-canon, if it were correct then the NCR flag should've been updated in New Vegas to match the single-headed bear shown in the Bible. However, the NCR flag retains the two-headed bear from Fallout 2, thus showing that Bible information has been disregarded in favour of Fallout 2 information.
And likewise, if Fallout 2 says the talking Deathclaw are still alive, then until some other game says they aren't, that hasn't changed. Besides, I can't believe Avellone was so small-minded enough to actually make a comment like that. I mean, the Fallout Universe is the perfect place to explore alien perspectives, to get a new view of things. It's a great way to break from binary thinking too, where if something is pretty, it can do no harm, and if something is ugly, it can do no good. Such simple moralistic views should be eschewed in favour of telling a truly interesting story.
If you're telling a fairytale, then the notion of pretty humans being good, and ugly monsters being bad is fine, but the Fallout Universe should be better than that. Otherwise it's no different than Star Wars, and that would make Avellone another George Lucas.

Having a doombeast scholar in a story is a great way to break people out of such ways of thinking. And in my opinion, if Fallout wants to be the high brow game it should be, then it shouldn't be so cowardly, it shouldn't be afraid to do that. Fallout 2 was not afraid to do that, and since no game has yet challenged Fallout 2, I'm going to stick with that.)
(Edit #3: Just to add to that, for those that missed it. I think that the removal of talking Deathclaws would be an incredibly populist, PC, and cowardly thing to do. And very typical of today's world.
"It's a dayumm ugly critter wot speaks wit' prittee-yer wurds'n I dew, how'n Sam Hill dus thet wurk? KILL IT!"
To be honest, we need more of this sort of thing, that being the talking Deathclaws, not narrow-mindedness, these days. Especially since binary thinking is at an all time historical high. Not less. The talking Deathclaw types would be the perfect thing to bring back to Fallout, to show that the developers aren't afraid of their roots. And aren't too afraid of public opinion to tell a good story.)