Assuming the pedal stays at the same angle relative to the bike frame, for example stays horizontal, I agree with the OP that anything above the pedal will still define a circle and the center of that circle will be correspondingly offset.

Imagine something long like a broom stick. The top end of it would clearly trace out a circle if the bottom end of it were moving in a circle. Again, assuming the stick remains at the same angle, I.E. straight up and down. Imagine tying two wheels together a with rod much like the coupling rods on drive wheels of steam locomotives.

As has been mentioned, since most of us will change our foot angle throughout the stroke, the contact point of the foot to the pedal, will not make a perfect circle.