It reads like you’re describing a series hybrid where the ICE feeds into an electric generator which feeds into a battery or electric motors.
That is not how most hybrids work. That’s how almost none of them works in fact, although it is how diesel electric works on large vehicles (an electric transmission essentially).
No, he's right. If you're interested, read about the Prius e-CVT transmission. It's pretty amazing.
Essentially, it connects the ICE and two different electric motors to the same drive shaft. By spinning the electric motor forwards, backwards or using it as a generator, it can regulate torque going to the wheels for a wide band of RPM. At the same time, torque and RPM coming out of the ICE are kept in a much smaller band.
But yes, the ICE is still directly connected to the wheels.
In a planetary gear setup, there's three different rotating planes you can hook onto. Traditionally one is free, two are rotating. But if instead, one is the output, another one the ICE engine (with electric boost) and the third one is another electric engine, the electric plane can change the influence of the output plane on the ICE plane, effectively intermediating the RPM and torque it sees.
That is not how most hybrids work. That’s how almost none of them works in fact, although it is how diesel electric works on large vehicles (an electric transmission essentially).