Some people do know that its going to be listed. https://www.reddit.com/r/CoinBase/comments/7kfbjj/will_coinb.... The user mukiwa2 said "Bitcoin Cash coming in the next few days!!" 2 days back in that thread and he even joked saying he knew an employee in Coinbase.

That response has since been deleted. I was just talking to my friend about this. Here is the snapshot: https://imgur.com/a/cLlp7