It is not entirely clear why Switzerland is not one of the allied countries.

I mean, Switzerland is explicitly neutral. They might be aligned with the US on quite a few matters, but they are not allied with the US.

https://en.wikipedia.org/wiki/Neutral_country

A neutral country is a state that is neutral towards belligerents in a specific war or holds itself as permanently neutral in all future conflicts (including avoiding entering into military alliances such as NATO, CSTO or the SCO). As a type of non-combatant status, nationals of neutral countries enjoy protection under the law of war from belligerent actions to a greater extent than other non-combatants such as enemy civilians and prisoners of war. Different countries interpret their neutrality differently:[1] some, such as Costa Rica have demilitarized, while Switzerland holds to “armed neutrality”, to deter aggression with a sizeable military, while barring itself from foreign deployment.

I’ll grant that “allied” is sometimes used in a looser sense, but I don’t think it’s very controversial to say that the US and Switzerland are not allied.

The US is allied with a lot of countries, but Switzerland isn’t in them:

https://old.reddit.com/r/MapPorn/comments/119l1w6/map_of_united_states_military_allies/

And I think that this came up pretty recently in the dispute over Switzerland refusing to provide ammunition for German Gepard SPAAGs that Germany had provided to Ukraine and where Rheinmetall’s production facility was in Switzerland. Switzerland said that they would not do so, that they considered themselves bound by their assertion of neutrality not to do so.

I could understand someone saying “requiring that a country be allied is an unnecessarily-strong requirement to do export of chips required for AI work” or something like that, debating that point, but “why is Switzerland not an allied country” doesn’t seem like a terribly difficult question to answer.

I think that it’s pretty clear at this point that both the US and China see the development of and possession of AI capabilities to have significant implications for military power moving forward.

Experts are already expressing their concerns, as these chips are used extensively in academic research as well as by many companies.

These technologies are already present in many areas and will be omnipresent in the coming months to years, says Olga Baranova on RTS television in French-speaking Switzerland

Yes, they’re dual use – they also have non-military applications. But one cannot create forms of those chips that can only be used for non-military purposes. If one has those chips, the military applications come with them.