Motorola announced that the Moto G7 and Motorola Android One devices will be getting the call screening functionality already available in Pixels BUT that it won't work on phones on the Verizon network (as well as on AT&T and T-Mobile -- Sprint is letting their subscribers have it). I have a Moto X4 Android One running Pie and should have this function. Anyone from VzW care to let us know why we can't use this function?
As someone who uses the Call Filter application, I can certainly understand the need to have this on your own device, so let's get down to business and get to the resolution for you. Call filter is not available on all devices, as shown here (http://spr.ly/6603EjGRH). Bring your own devices (BYOD - non-Verizon phones) like the Moto X4 you're using will fall into this category and are not compatible with the Call Filter app. For these devices, the Call Filter app is not pre-loaded nor available for download in the Google Play Store.
I do apologize for being the bearer of bad news, but at this time there is no estimate on when Call Filter will be able to be downloaded on non-Verizon phones.