Got mine changed recently from Honda official service center in Karachi, Nazimabad.
They also changed from the drain bolt and 3 liters of transmission fluid came out and 3 liters were exactly added.
Before changing they (Honda service supervisor) also told me that 1 in 10 cars may give transmission issues after changing transmission fluid even if the car was running perfectly fine before the oil change.
Completely changing the full transmission fluid required removing the torque converter which is not recommended.
You just change 3 liters of old oil, add new honda genuine oil, pray that your transmission survives, then after 5 to 6 months again change 3 liters.
This is the safest way to completely change your transmission fluid if your unsure about your transmission history.