According to the preface of Night, has Wiesel's perspective shifted in any way over the years?

In looking at Night and its Preface, it is clear that Wiesel remained committed to his insistence on compassion.

I tend to think that reading Night should precede reading its Preface.  Doing so provides a frame of reference that shows how Wiesel's perspective had not changed over the years.  If anything, it hardened into believing now more than ever that the information presented in Night is of vital importance.

Wiesel's perspective about compassion did not change over the years.  In Night, he shows a tremendous amount of compassion.  He includes voices like Moshe the Beadle and Madame Schachter in his narrative, people who were silenced by human indifference.   He pays attention to the weak and those who suffer, such as when he talks about remembering the faces of the slaughtered children.  He displays an acute sensitivity to moments where individual pain and suffering illuminated the Holocaust's horror. These ideas are also emphasized in the book's Preface:  

There are those who tell me that I survived in order to write this text. I am not convinced. I don't know how I survived; I was weak, rather shy; I did nothing to save myself. A miracle? Certainly not.

If heaven could or would perform a miracle for me, why not for others more deserving than myself?

It was nothing more than chance. However, having survived, I needed to give some meaning to my survival. Was it to protect that meaning that I set to paper an experience in which nothing made any sense?

Wiesel does not consider his survival extraordinary.  In the Preface, he displays compassion towards the millions of others who were not saved.

The empathetic need to "bear witness" to human suffering defined Wiesel's life.  He felt a responsibility to speak out against genocide because he was saved. His life's writings, thinking, and advocacy emphasized the dangers of indifference.  They also highlight the moral implications of silence when action must be taken.  Time had not diminished his sensitivity to the pain that others experienced. His compassion was present when he wrote Night, a virtue that he never abandoned.