Are they just assembled in Japan from Chinese-manufactured chips? Do Intel, AMD, etc. even manufacture outside of China anymore?

Intel factories are around the world (US, Europe, Israel, Malaysia), but none in China. See ([1]).

AMD uses TSMC (Taiwan) and GlobalFoundries (USA, Europe, Singapore [2]).

So, answering your narrow question: yes, these chips are manufactured outside of China.

But the answer to your wider question is more complex: supply chain is so globalized that there will always be some components or subassemblies manufactured in China in any laptop, unless it's a state-sponsored multi-year effort to not have any.

1. https://en.wikipedia.org/wiki/List_of_Intel_manufacturing_si...

2. https://en.wikipedia.org/wiki/GlobalFoundries

Thank you for this info! I didn't know that, and am glad to have learned.

One challenge with importing Japanese laptops is not being able to order them with a US keyboard layout, many ship exclusively with a JIS keyboard layout.

I have seen local distributors add stickers on the keys. The layout is a little bit different but it's not so bad.