Who they voted for is inconsequential. As McDaniel’s spokesperson has said, all they need to do is throw the result into question. If you can prove a reasonable doubt as to the result, with the right judge, it will be overturned.
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If the data was available to determine the total votes for each candidate that would be disqualified then a recount would be in order not a new election.
So who they voted for is very, very consequential. But, as far as we know, the connection between the voter and the ballot is not available. If so the best we can hope for is a new election as you noted.
OTOH, I am yet to see anything definitive concerning the lack of tracking from voter to ballot. We are all just assuming that connection is not possible.
Under normal circumstances, you are absolutely correct, but Mississippi is one of something like 2 states that do not have a recount procedure on the books, which is why one is not on the cards.
This will be about throwing the result into question. I think that is what happened with the Hattiesburg mayoral race