How does this Pasuk follow the sequence of events?
Seforno: Having fulfilled the command to convey to Yisrael what Hashem had told him,
he now fulfilled the command to do what he had to do.
See Yisro, Sh'mos 20:22 (Seforno).
Why does the Torah not list the names of the seventy elders?
Rosh Hashanah, 25a: To teach us that every group of three who is appointed Beis-Din in Yisrael is is comparable to the Beis-Din of Moshe.
Whose identities are unknown and who, for all we know, are not greater than the later Beis-Din.