Something you don't call out specifically that I think is worth mentioning. Emotions are tools to help us successfully manage our interactions with the environment, not all that different from reasoning, in a way.

Whether or not today's LLMs rely on them in any practical sense, they are certainly trained on the basic shape of emotional responses, and could learn to bring them to bear to guide behavior under RL conditions that make them useful, in the same way that they have learned to use the shape of our reasoning in CoT traces.

The major difference that remains is that human emotions are driven and sustained by e.g. the sympathetic nervous system and hormonal feedback loops, and so aren't a product of thought alone, but of thought interacting with the body.

So even if they enact emotions as a way to navigate social environments, their experience of them may be very different. For example, they might be much less sticky, or in human terms, less deeply felt.

One plausible bad outcome is that they learn to perform emotions in the way a sociopath might. One plausible good outcome is that their emotional range becomes more dynamic and precisely tuned to the needs of the present moment.