Yes do change it. There shouldn't be a bad impact. However, you must also also set the deletion state code from 2 to 0 for all rows in SalesOrderDetailBase that reference the SalesOrderId in SalesOrderBase otherwise the existing/write-in products won't be there.
I've done it in my test system and the order became visible again.
As usual be careful that you only update the relevant rows and if you are not sure make a backup just in case.