The anycast is for the /24 those IP addresses share (first.three.octects.0/24) But if you look those /24 are Arin.

Dig +trace shows the recursive lookup (forwarders) used for your NS.

They almost always end up Arin and arpa. I've troubleshot some connection issues between different data centers and transit providers and found root hint oddities I just escalate to my supervisor

That part makes sense to me. If one has ever tried to announce an ARIN IP in the EU or a RIPE IP in the US they will send warnings that the allocations will be pulled back if that is not fixed. Been there, done that. The root servers were created in the US. To have RIPE IP addresses I would imagine would require ARIN to set up some partnership but there again that gets into management and politics in their organization that I am unaware of. Every time I start to read any of their minutes they lose me after the first paragraph.

If the concern is that the US would somehow break the root servers and disrupt many trillions of dollars of trade I guess that is technically possible but probably unlikely given the amount of trade, tariffs, tax revenue that would impact would end anyone's political career and things would be reverted quickly in my opinion.