Beating Around the Bush of Knowledge

In Genesis 19.31, 38:16, and 30:16 the expression "come in to" means to have sex.

Although aspects of the Genesis narrative are no doubt ancient, perhaps even tied to Gilgamesh from the third century BCE,  we understand most of the document was redacted much later around the Babylonian Exile in 586 BCE. The words "come in to" only appear one other time in the NRSV Hebrew Bible, which is in Esther 4:11. This book likely dates to Mordecai and the third or fourth century BCE,  or even to the late second or early first century, according to Jewish tradition.

So what are we to make of the words "come into" in Genesis 6:20? Should the expression be interpreted in the same way as it is elsewhere in Genesis under the guiding hand of J, E, D and P, or should it receive the much more contemporary meaning conveyed in Esther?

As we used to hear on Laugh-In, "Very interesting, but stupid."