Verizon Pixels can have the chance of being bootloader locked. Other pixels can still install other OSes.

Note that according to @final I'm wrong. You will be able to unlock in 3 months. Verizon phones are the only problem. 

Son of a b. 

Shopstr it is. 

Thanks for the heads up.

TheWildHustle

I don't think that's the "unlocked" you need. That just allows you to switch carriers. Your bootloader needs to be unlocked.  Once a carrier has the phone it can't be unlocked. @final can correct me if I'm wrong. You need to buy a phone with an unlocked bootloader from google. I know from experience. 

siggy47

tech

GrapheneOS: The Purpose, The Strategy, and The Why [Article]

final

Gotta wait 3 months for tmob to unlock my pixel. 
The Wife is headed down a similar rabbithole with me, she's way more privacy/security minded. 