I believe it's an Android Oreo feature, not specific to the Pixel. I picked up a Nokia 6 for my dad and was surprised to see it blocking. Google Voice has had

I believe it's an Android Oreo feature, not specific to the Pixel. I picked up a Nokia 6 for my dad and was surprised to see it blocking. Google Voice has had spam lists forever, it's likely they are pooling the data from there. T-Mobile does have the ScamID/block thing that can be controlled by shortcode. Documentation here https://explore.t-mobile.com/callprotection https://explore.t-mobile.com/callprotection