It was named after astronomer Johannes Kepler and followed a Earth-trailing heliocentric orbit.

If it's the sun, it's a heliocentric orbit.

So, the old Earth-moon system was, as a whole, revolving around the sun in a heliocentric orbit.

This even happens naturally sometimes: an asteroid in a heliocentric orbit will wander close to L1 and get captured by the Earth.

When we refer to the sun as a planet, it does not negate our comprehension of the heliocentric orbit of the planets.