`RewindBlockIndex` was made to allow nodes upgrading to new consensus rules post-segwit fork to 
download new consensus data (i.e witnesses) without having to go through a whole IBD. It has been pointed than now really few pre-segwit nodes care to upgrade and that this logic may be irrelevant.

See https://github.com/bitcoin/bitcoin/pull/17737#discussion_r358514335 in review  of #17737 for more context pointers.
if (g_txindex) {
        g_txindex->Stop();
        g_txindex.reset();
    }
    ForEachBlockFilterIndex([](BlockFilterIndex& index) { index.Stop(); });
    DestroyAllBlockFilterIndexes();
    
    
    
    
    
    if (node.chainman) {
        LOCK(cs_main);
        for (CChainState* chainstate : node.chainman->GetAll()) {
            if (chainstate->CanFlushToDisk()) {
                chainstate->ForceFlushStateToDisk();
                chainstate->ResetCoinsViews();
            }
        }
        pblocktree.reset();
    }
    for (const auto& client : node.chain_clients) {
        client->stop();
    }
#if ENABLE_ZMQ
    if (g_zmq_notification_interface) {
        UnregisterValidationInterface(g_zmq_notification_interface);
        delete g_zmq_notification_interface;
        g_zmq_notification_interface = nullptr;
    }