I cannot se how the device is a buck charger when charging and a boost on the output
Buck Regulator for Charging Battery.
 =  Stepdown from 5V to Battery (CC then 4.2V then cutoff)

Boost Regulator as OTG (on-the-go USB power)
 = Step-Up from Battery to USB or 3~4V  to 5V

It is consistent and correct.

I have redrawn the switches to show more clearly the topology used.