Earlier quoted context omitted.
In general I don't think the best time and place to make a tribute to your dad's dead wife is at his new wife's wedding. I hope it wasn't passive aggressive.
I would like to think that a woman marrying a man who has gone through this would be quite well acquainted with (and respect) the fact that the man's love for the woman who passed would not be replaced by the new love.
The problem with software people is they too often treat people like logical code. Hence the stereotypes.
Feynman's letter itself is beautiful precisely because it isn't logical. Not only because he was writing to a dead person, but also beause he so deeply respected their intimacy and cherished her feelings even after her death that he kept the letter private. In other words it was a real letter not a memorial or tribute. It would have been quite logical to publish it in her honor. But he did not!