Shang era oracle bones attest to the Shang fighting(sometimes cooperating) with an entity known as the Ren Fang/Shi Fang(人方/尸方)(Fang being a polity independent of Shang control),which was also known as Yi Fang(夷方) since Ren and Shi have the same meaning as Yi.

While the precise location(though within Shandong) of the Ren Fang is debated amongst scholars due to its inclusion of multiple groups ie Qi(杞),You(攸),Suo(索) and Huai( 淮).

During the western Zhou the peripheral states of Eastern Shandong(Who were ruled by indigenous chieftains not feudal lords of Shang or Zhou stock) were all labeled Dong Yi(東夷) yet it is clear from their own inscriptions that they had their own names.(While the Huai Yi(淮夷) were treated as a separate culture).

Minna Wu divides the polities in Shandong into three categories.

1.Feudal lords descended from the cadet branches of the Zhou imperial family or staunch Zhou allies. ie Lu(魯),Qi(齊),Cheng(郕),Tan(譚),Sui(隨) and Teng(滕) etc.

2.Indigenous states that were never under Shang/Zhou control with a culture foreign to the Shang/Zhou polities. ie Lai(萊),Ju(莒),Zhu(邾),Zeng,(鄫),Shi(邿) etc.

3.States that were either allied to the Shang elite or colonies directly controlled by the Shang. ie Ji(紀),Xue(薛)

To make a long story short Qi in conjunction with with other Zhou vassals warred with the Dong Yi polities or allied with them to attack Huai Yi polities resulting in a blend of Shang,Zhou and Dong Yi material goods.(Forming a local culture not unlike the Qin or the Chu,though unlike the the others did not declare themselves as a separate and superior culture.)

During the Qin-Han era the Dong Yi polities of Shandong were long extinguished and assimilated by Qi,the term was recycled to refer to a diverse group of foreign cultures.

In the end there isn't any proof that the Ren Fang or Dong Yi spoke a Koreanic language or that Koreanic speakers existed in Northern China.

For further information considering reading "On the Periphery of a Great “Empire”: Secondary Formation of States and Their Material Basis in the Shandong Peninsula during the Late Bronze Age, ca. 1000-500 B.C.E"