It seems that Intel has implemented the ULP (Ultra Low Power Mode) for its Ethernet products since long time ago. For example, In I218 datasheet https://www.mouser.com/datasheet/2/612/i218-ethernet-connection-datasheet-275854.pdf, I can find  ULP related revision history:

2.2   September 2013  

• Revised section 6.3.1.4.2 (EEE LPI Unsupported Features; added network proxy offload bullet).

• Revised section 6.4 (The Intel® Ethernet Connection I218 Ultra Low Power (ULP); LED tri-state mode bullet).

The earlier products like I210-LM may support ULP as well. But just want to know when was ULP (Ultra Low Power Mode) implemented for Intel Ethernet Adapters for the first time. Thanks!