I think the whole chest and head resonance/voice thing is a bit complicated - same as the term falsetto.
Basically Dr Kim recognizes there are changes in resonance that need to happen to feminize the voice. His Website states that
QuoteAlso, the tone quality of the voice and resonance of the sound can be changed into a more female voice by changing the shape of the pharyngeal cavity through the patients' motivation, and by attending voice clinics and voice rehabilitations.
- which means to change resonance. He just does not call it chest and head resonance but sometimes seems to speak about different phonation patterns.
Head voice and chest voice is something different , it is just two of the main registers for speaking that are connected to pitch - at some pitch, the voice changes quality in a noticeable way, often associated with a "passagio" or even a voice break. This is not changed by surgery, it has more to do with the muscles interacting with each other. The "chest voice" is the normal speaking voice. It goes from your lower-mid range through most of your regular speaking pitches. The head voice is the singing voice - it starts at higher pitches, D4 for me, G4 for others. The quality of both voices can be blended, mixed or pushed into the other pitch area to a degree, giving a soft transition.
According to my SLT her transition pitch is also at a D4 and for her, the head voice is part of speaking, but only in some short phases. So for example the classical "Oh my god" expression may start out with a very high pitch and with head voice and then drop into regular speaking pitch and chest voice. So this is kind of fascinationg because it means that many women will use a mix of chest and head voice while speaking with voice melody and intonations, while men will not do that, since their speaking pitch is much more below that transition pitch and their voices are usually more monotonous.