I think you misquoted the text. Under "To Start Playing", the sixth bullet point reads:
✦ Unless the adventure says otherwise, place the Start tile in the center of the table and place two Healing Surge tokens beside it. These are the group’s surges for this adventure.
which tells you the general rule. The tenth bullet point reads:
✦ Check the “Starting Awards” section of the adventure’s setup to see how many Healing Surge tokens the Heroes start with, as well as any starting Treasure cards.
which tells you that the adventure you choose may have an exception to the general rule. They are not added.