I'm looking to attach 16 10k pots to an MCP23017 i2c GPIO expander, and connect that to a Teensy 4.1. The i2c ports on the 4.1 are on the same pins as the analog pins.

Would the i2c ports on the 4.1 automatically work as ADC converters, or would I need to get an additional ADC breakout to convert the analog potentiometers to digital via the i2c bus?

I'm very new to these concepts to let me know if that is unclear. Thank you.