Emeka,
The key point here is that there is no alteration of Bank Statement data - the only thing being modified is the Payment (or Payment Allocation).
The Bank Statement itself is not the main driver of financial postings - instead, it holds a list of Payment Allocations. These Payment Allocations can be altered after posting, because they do not alter the cash clearing balances.
In this scenario, as it turns out, nothing on the Bank Statement was really altered (instead, a reversing entry was created).
Even still, it's possible to change the allocation on the Bank Statement without reversing the statement itself. For example, I've had a client accidentally book a line on a Bank Statement towards the wrong check (it should have been for a different check for a same amount). In that case, they reversed the Payment Allocation and created a different Payment Allocation on the existing posted Bank Statement. At no point did the Bank Statement need to be reversed.
Even if the reversal occurred within a different month, that would only drive the reversal date posting - the line for the original amount should still remain on the original statement. So there's no change to financials within the month of the original transaction.
The only occasion that i can see the need to reverse a Bank Statement is when the actual opening or closing balances are different than what was originally entered.
I can see that earlier in the thread you rightly identified that as the reason for reversal of a bank statement, but i jumped in as i wanted to clarify the scenario further - i always want to make sure that something requiring that level of manual work is truly the only option.
Not trying to step on anyone's toes here - just wanted to hopefully prevent a lot of manual work.