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.
* Marks all outputs in each one of the destinations dirty, so their cache is
     * reset and does not return outdated information.
     */
    void MarkDestinationsDirty(const std::set<CTxDestination>& destinations) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool GetNewDestination(const OutputType type, const std::string label, CTxDestination& dest, bilingual_str& error);
    bool GetNewChangeDestination(const OutputType type, CTxDestination& dest, bilingual_str& error);
    isminetype IsMine(const CTxDestination& dest) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    isminetype IsMine(const CScript& script) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    /**
     * Returns amount of debit if the input matches the
     * filter, otherwise returns 0
     */
    CAmount GetDebit(const CTxIn& txin, const isminefilter& filter) const;
    isminetype IsMine(const CTxOut& txout) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool IsMine(const CTransaction& tx) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    
    bool IsFromMe(const CTransaction& tx) const;
    CAmount GetDebit(const CTransaction& tx, const isminefilter& filter) const;
    void chainStateFlushed(const CBlockLocator& loc) override;
    DBErrors LoadWallet();
    DBErrors ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256>& vHashOut) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& purpose);
    bool DelAddressBook(const CTxDestination& address);
    bool IsAddressUsed(const CTxDestination& dest) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool SetAddressUsed(WalletBatch& batch, const CTxDestination& dest, bool used) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    std::vector<std::string> GetAddressReceiveRequests() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool SetAddressReceiveRequest(WalletBatch& batch, const CTxDestination& dest, const std::string& id, const std::string& value) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    unsigned int GetKeyPoolSize() const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    
    void SetMinVersion(enum WalletFeature, WalletBatch* batch_in = nullptr) override;