I ran bitcoin-qt with an old wallet, causing it to rescan, then stopped it with a SIGINT signal, resulting in the following log. Nothing unexpected, so far:
```
2022-03-05T16:01:03Z init message: Loading wallet…
2022-03-05T16:01:03Z BerkeleyEnvironment::Open: LogDir=…/.bitcoin/database ErrorFile=…/.bitcoin/db.log
2022-03-05T15:57:18Z [walletname.dat] Wallet File Version = 159900
2022-03-05T15:57:18Z [walletname.dat] Keys: 2397 plaintext, 0 encrypted, 2397 w/ metadata, 2397 total. Unknown wallet records: 0
2022-03-05T15:57:18Z [walletname.dat] Wallet completed loading in              65ms
2022-03-05T15:57:18Z init message: Rescanning…
2022-03-05T15:57:18Z [walletname.dat] Rescanning last 134072 blocks (from block 591711)...
2022-03-05T15:57:18Z [walletname.dat] Rescan started from block 000000000000000000075fcc1872da61f45bcfd0e0bb36b7c8cb45e7a328ad41...
2022-03-05T15:58:18Z [walletname.dat] Still rescanning. At block 593552. Progress=0.632716
2022-03-05T15:59:18Z [walletname.dat] Still rescanning. At block 595458. Progress=0.638084
2022-03-05T15:59:37Z [walletname.dat] Rescan interrupted by shutdown request at block 596080. Progress=0.639932
2022-03-05T15:59:37Z Error: Failed to rescan the wallet during initialization
2022-03-05T15:59:41Z GUI: initializeResult : Initialization result:  false
2022-03-05T15:59:41Z GUI: requestShutdown : Requesting shutdown
2022-03-05T15:59:41Z GUI: Running Shutdown in thread
2022-03-05T15:59:41Z Shutdown: In progress...
2022-03-05T15:59:41Z scheduler thread exit
2022-03-05T15:59:42Z Shutdown: done
2022-03-05T15:59:42Z GUI: Shutdown finished
2022-03-05T15:59:42Z GUI: ~InitExecutor : Stopping thread
2022-03-05T15:59:42Z GUI: ~InitExecutor : Stopped thread
```

However, the next time it was launched, the rescan didn't continue, nor did it start over. It seems to have been skipped?
```
2022-03-05T16:01:03Z init message: Loading wallet…
2022-03-05T16:01:03Z BerkeleyEnvironment::Open: LogDir=…/.bitcoin/database ErrorFile=…/.bitcoin/db.log
2022-03-05T16:01:03Z [walletname.dat] Wallet File Version = 159900
2022-03-05T16:01:03Z [walletname.dat] Keys: 2397 plaintext, 0 encrypted, 2397 w/ metadata, 2397 total. Unknown wallet records: 0
2022-03-05T16:01:03Z [walletname.dat] Wallet completed loading in              91ms
2022-03-05T16:01:03Z [walletname.dat] setKeyPool.size() = 2000
2022-03-05T16:01:03Z [walletname.dat] mapWallet.size() = 378
2022-03-05T16:01:03Z [walletname.dat] m_address_book.size() = 183
2022-03-05T16:01:03Z Loaded 2 addresses from "anchors.dat"
```

I didn't investigate deeply, but could it be that despite the failed rescan, the new tip block was stored in the wallet? if so, this would be confusing.
bool fUpdated = false;
    bool is_mine;
    {
        LOCK(cs_);
        std::map<CTxDestination, CAddressBookData>::iterator mi = m_address_book.find(address);
        fUpdated = (mi != m_address_book.end() && !mi->second.IsChange());
        m_address_book[address].SetLabel(strName);
        if (!strPurpose.empty()) /* update 
            m_address_book[address].purpose = strPurpose;
        is_mine = IsMine(address) != ISMINE_NO;
    }
    NotifyAddressBookChanged(address, strName, is_mine,
                             strPurpose, (fUpdated ? CT_UPDATED : CT_NEW));
    if (!strPurpose.empty() && !batch.WritePurpose(EncodeDestination(address), strPurpose))
        return false;
    return batch.WriteName(EncodeDestination(address), strName);
}
bool CWaet::SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& strPurpose)
{
    WaetBatch batch(GetDatabase());
    return SetAddressBookWithDB(batch, address, strName, strPurpose);
}
bool CWaet::DelAddressBook(const CTxDestination& address)
{
    bool is_mine;
    WaetBatch batch(GetDatabase());
    {
        LOCK(cs_);
        //  we want to delete receiving addresses, we need to take care that DestData "used" (and possibly newer DestData) gets preserved (and the "deleted" address transformed into a change entry instead of actuay being deleted)
        // NOTE: This isn't a problem for sending addresses because they never have any DestData yet!