I’m not sure how you’re using the word sentience. Rudimentary sentience is simply self awareness which some animals have; chimps and gorillas come to mind. Some animals keep pets, which requires a differentiation from themselves and their chosen pets, and empathy.
The gorilla, Koko, has been taught over 1,000 ASL signs, understands over 2,000 words in English, and communicates with humans. She has also invented a few signs to describe things when she finds ASL lacking. She has been able to choose mates from video, differentiating one from the other in a two dimensional format without any other senses in play, such as smell. She has chosen one intended pet cat from the other in a litter. Then she names her pets. She mourns the loss of loved ones, suffers separation anxiety from friends, and becomes depressed, such as when her pet cat was killed by a car. She experiences loneliness. An adult male companion gorilla, Michael, learned over 600 ASL signs, with Koko’s assistance, and was able to describe decades-old childhood memories of the murder of his mother by west African poachers. After doing so, he signed “bad, sad, bad,” then retreated to a corner and was quiet for the rest of the session. These gorillas also exhibit evidence of pride, modesty, and embarrassment.
I believe all of this requires sentience. So, the leap isn’t very far at all, at least in the case of gorillas. The will to communicate is there and the FOXp2 speech gene might provide very interesting revelations, if transferable and if gorillas have the equipment for speech as we know it.
At no time has Koko or any other of the communicative gorillas considered humans as higher beings, or god-like. Only providers of food, conversation, and amusement. I haven’t seen anything on Dr. Paterson discussing a gorilla origin story or the idea of a creator with these gorillas, but I would be surprised if the subject hasn’t come up. Maybe gorillas don’t concern themselves with such things. I never did until I reached my late 40s and witnessed an inordinate amount of mortality. Maybe Dr. Paterson’s gorillas wouldn’t know anything of traditional gorilla lore, if it exists, because they were all removed from their societies at a very young age. However, Michael’s exhibition of long memory and apparent reflexion upon a perplexing personal tragedy certainly appears to be the seed of rationale and introduces the possibility rudimentary philosophizing. A lot of this is on YouTube. It is quite amazing to watch. Quite poignant.