do you think that Anja and Vladek would approve of this ending?

I believe that Anja would be happy that Vladek was upfront about the diaries, and that he shared with Art the fact she'd hoped he be interested someday. I don't believe she'd be happy that Vladek burned them..... they weren't his to burn. I also don't think she'd want them to cause a rift between her son and his father, but Art would probably have her support. Mothers and their sons.....