I am the one flashing a new phone with Graphene and loading the apks. This is meant for those who would like the privacy gains but aren't totally comfortable doing it.  

 Purism claims you can audit the supply chain of their phones. They are not very usable yet though. 

 This offers users an anon phone from random supplier flashed with Graphene OS by myself. If they so choose. You can also reflash or ask for it stock, I don't care.