It uses the SATA interface, instead of the SD card interface. Different signalling.
Also, it's designed to be permanently soldered to the PCB - like an eMMC chip.
Yes but the PCB doesn't need to mean that it is the motherboard of an embedded system. It could be the control board of a hard drive or a SATA expansion module.
But when I think about it, I'm not sure of the meaning of the embedded SATA controller if the chip is supposed to be on a SATA module. If you use several of these chips on such a module, then a controller that handles the separate chips must be included anyway. Perhaps a microPCIe module would include say an 8-channel SAS/SATAIII controller and 8 of these chips in a raid configuration.