I went back and re-watched the Goff comment (around the 53-54 minute mark), and I do not agree.
McVay talked for a good 3-4 minutes about Stafford. It was positive and clear that, while things remained fluid and the outcome was uncertain, he praised Stafford and wants him back ... if possible.
The Goff comment was in reply to a compliment from Fitzpatrick about the 'transparency' of communication from McVay, and how it was a strength of his and appreciated by players. McVay's response to that compliment was the Goff reference and how he could have handeled things better in his communication with Goff (this is something McVay has spoken of in the past).
McVay's point in raising the Goff situation was that he wanted to learn and grow from past mistakes. However, I did not interpret that as specific to only when players are traded.