How about calls originated outside NorthAmerica? (these countries won´t follow this STIR/SHAKEN protocol) Are these calls all be treated as "possible spoofed CLI" calls?

1. General Battling Robocallers with STIR/SHAKEN
1

Calls from outside the US/Canada should be signed by the international gateway service provider with attestation “C”. While the call is un-trusted, it leaves a digital breadcrumb to the operator and source of the call.