I’ve pre-ordered my iPhone Pro with trade-in. When I went to pick up, I gave my previous phone to store for trade-in and received an email. But now I still get emails from Apple that they still haven’t received my device.
iPhone XS
Just ignore them. There's no way to turn them off and they are likely prompted from the partner they use to receive traded phones. As long as you got your trade value, there's nothing to worry about.