Haha they definitely can’t claim there was no space for a headphone jack indeed.
But I mean, electronics is tiny, it can go with the same motherboard as a phone. The only thing it needs to be larger is a battery, and that’s a capacity/weight balance.
Speakers maybe, but that’s also a function of thinness so I don’t know how much of a difference size makes. Thin laptops sound just as crappy as anything else thin unless the vendor shells out for some expensive units.