I am bilingual. I personally do not dream in a specific language. When I wake up, I'll remember scenes, people, feelings and actions. Sometimes there are dialogues in French, but it's rare.

As for thoughts, I often think in French or English, but for a lot of thoughts, no language is involved. For example, I do not think "I must pay my electricity bill" or "I should do some laundry today".

When people make vector embeddings for words, it's fairly common that the embedding for one language is just a rotation of the embedding for the synonym in another language. So I think the higher level (and lower dimensional) representations of thoughts could be pretty consistent across native languages. Even though you might perceive your thoughts to be formulated in your native language, your brain almost certainly generates that representation from another, which is probably more universal. That means we could exchange these universal representations of thoughts and our own brains would do the "translation" as necessary.

I don't think it works that way, either. When you reach for a door, do you first think "I'm going to reach for that door," in English? Or do you just think it wordlessly? For me, personally, when I inspect how I'm thinking, I really do think wordlessly a lot of the time. It's only in communicating my thoughts to others that my ideas become verbalized, or if I'm in a verbalizing mood, I might be talking to myself. But when I've gone hours without talking to someone, I'm probably not going to verbalize much in my head.

He may be implying a hybrid, which does non-spoken translation but also add emotional queues in order to make things clear.