`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.
return true;
    }
    if (!txdata.m_spent_outputs_ready) {
        std::vector<CTxOut> spent_outputs;
        spent_outputs.reserve(tx.vin.size());
        for (const auto& txin : tx.vin) {
            const COutPoint& prevout = txin.prevout;
            const Coin& coin = inputs.AccessCoin(prevout);
            assert(!coin.IsSpent());
            spent_outputs.emplace_back(coin.out);
        }
        txdata.Init(tx, std::move(spent_outputs));
    }
    assert(txdata.m_spent_outputs.size() == tx.vin.size());
    for (unsigned int i = 0; i < tx.vin.size(); i++) {
        
        
        
        
        
        
        CScriptCheck check(txdata.m_spent_outputs[i], tx, i, flags, cacheSigStore, &txdata);
        if (pvChecks) {
            pvChecks->push_back(CScriptCheck());
            check.swap(pvChecks->back());
        } else if (!check()) {
            if (flags & STANDARD_NOT_MANDATORY_VERIFY_FLAGS) {