I've been getting that same notice. As soon as my Carplay connects, the Wallet message disappears, so I suspect others may be getting it but not seeing it. You really have to be watching your phone screen or it will flash up and then disappear without you ever seeing it.
I think it's a bit of a red herring for us. Until Mopar turns on the function in the RAM app, I think there is simply no way to get the digital key into the Apple Wallet. I think it's the app, talking to Mopar on the back end, that will generate that 8 digit key code and put it in my Apple Wallet for me.
So, we continue to wait...