I'm not a lawyer, so this isn't legal advice. However....
The first question is: Who is the owner of the fence? Although it divided your yards, it undoubtedly was on the property of either you or your neighbor. If it was on your property, it's clearly your responsibility.
If the fence was on your neighbor's property, then the decision is up to the new owners. First, is there some community ordinance or regulation requiring the fence? If so, then the new owners would be bound by the regulation. If there's no requirement that a fence be in place, then the new owners shouldn't have to be required to replace the fence.
Recognize, too, that at an auction a likely scenario (in today's market) is that it doesn't sell at it becomes bank-owned. Also possible is that an investor will purchase the property. Neither one is likely to be interested in sinking money into a new fence, if they don't have to. And if the fence is on your property, the odds of either a bank or an investor paying you to help repair your fence are quite unlikely.
If you feel very strongly on the matter, or if the facts are different than those I've guessed at, certainly consult a lawyer.