Assume that a given question has several answers.
So in the answer part there are 3 button "Active", "Oldest" and "Vote"
When we clique on "oldest", we lead to a unique answer.
Is this unique answer the first answer to the question?
I doubt that the answer to this meta question is affirmative since it does not work for example on this question
Finding a 1-form adapted to a smooth flow
On the other hand the situation is different for the following question with several answers
If $x_{n+1}= \frac{nx_{n}^2+1}{n+1}$ then $x_{n}=1$
So what does "oldest" signify?