How is this genealogy connected with the story of Exodus 6 and 7?

Exode 6:14–27 (NEG79)

14 Voici les chefs de leurs familles. Fils de Ruben, premier-né d'Israël: Hénoc, Pallu, Hetsron et Carmi. Ce sont là les familles de Ruben.

You can see that in how it is put together. Exodus 6:10–30 form another chiasm.

a. God’s instruction to Moses to go to Pharaoh, and Moses’ protest (Exodus 6:10–12

b. God addresses Moses and Aaron (Exodus 6:13)

c. Genealogy (Exodus 6:14–25)

b' God addresses Moses and Aaron (Exodus 6:26–27)

a' God’s instruction to Moses to go to Pharaoh, and Moses’ protest (Exodus 6:28–30)

Exodus 6:28 connects with Exodus 6:10–12, after which it continues with God’s reaction to Moses’ protest (Exodus 7:1–7).