Allright, so what do we get here?

Motherboard, think it's I2C touchpad, the keyboard and light and motherboard interconnect board with a few chips

You can say why they give a interconnect board, but the motherboard is not pretty crammed with stuff.

Especially when compared to the 2012 model, as they added a USB-C and a card reader. Plus some unnamed ports.

But hey, remember that this chassis is also used for the precision mobile workstations. That might be explaining all the unsoldered ports (and the SATA settings in BIOS)