The previous models of the Raspberry Pi used different circuits to connect its 5 V power rail to the HDMI connector, i.e. How much current can I draw from each model's HDMI socket?
Especially the latest Pi 3B+ uses a RT9741CGV High-side power switch.
The Pi 4's schematics does not show something equivalent, i.e. 5V_HDMI is only listed as being connected to the HDMI connectors without revealing the respective power circuit.
What is the function of the ICs labelled "BV=92R" and "JGJ 851" with respect to the HDMI ports?