That was definitely the case on the FP1.
From the thread on USB Power Delivery:
https://www.xda-developers.com/google-new-android-devices-type-c-support-usb-pd/
This page shows the Google certification requirements for USB ports, and states that the device should have a possibility to rotate the screen such that the port is on the bottom. As the FP2 (since Android 7, I believe) is able to turn the screen upside-down, it seems to me that you can be creative with this, though.