Can you please specify the Product Part Number and Firmware you are referring?
I made a dock and used the CYPD4236-40LQXI_dock sample code.
APP_EVT_TYPEC_ATTACH signifies Type C attach event i.e when the terminations Rp or Rd is detected (detecting a port partner is connected).
APP_EVT_CONNECT signifies Type - C connect detected i.e. the PD contract is established with the port partner.