My Understanding of the carrier apps/bloat on Nexus 6 when I had one. I would do a fresh factory reset then insert an AT&T sim. After the initial setup it would download DT_Ignite program. That is the program that would install the carrier bloat from each carrier.doesnt google make a rom for essentially every carrier for the nexus 6? I know ATT users dont get OTAs until ATT approves them (and there was att bloat), tmobile and fi have their own specific roms. I believe google said there will only be one rom for all nexus 5x and 6p, maybe refusing to sell through carriers is a means to that end?
I tried doing a factory wipe/reset then insert a VZW sim and got the same results.
The only time it seemed to not get it was when I flashed a stock rom through a custom recovery.
http://www.androidauthority.com/carriers-install-bloatware-without-permission-571052/