It seems that it would otherwise silently skip the rescan for pre-backup used keys that are still waiting to be generated into the keypool?

See also #11249 
}
    // H
    // c
    if (reason == MemPoolRemovalReasonCONFLICT) {
        // T
        // S
        //
        // 1
        //    
        //    
        //    
        //    
        // 2
        //    
        //    
        //    
        //    
        //    
        // 3
        //    
        //    
        //    
        //
        // N
        // w
        // d
        // i
        // h
        SyncTransaction(tx, TxStateInactive{});
    }