The question that was posted first had a recent change on that question based on the comments or from answers, for which I would have earlier answered. How does stackoverflow or stackexchange do justfication for my answer for the unedited question. Incidentally, I would say my answer would look too foolish to the newly updated question for a reader.
What if I am not checking my stackexchange account for a period of time (during which question modified), and my questions voted down? Is this not against the valuable resources of stackexchange?
Edit of my question based on answers.
1.If I have to change the answer based for the newly edited question, should I always have to look at the questions I answered for edits in the old question.
2.If i have to delete my answer for the newly edited question, what justification will the community give to the readers who read my answer before I deleted my answer.