addmultisigaddress creates an address respecting the setting, being unable to generate a specific type of address without also adding it to the wallet seems wrong.

I suppose in the future `addresstype` may be refactored to be wallet-specific, which would leave this non-wallet rpc call without an argument. Perhaps there should just be an optional parameter to set it.
bool AddWatchOnly(const CScript& dest, int64_t nCreateTime) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool RemoveWatchOnly(const CScript &dest) override EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    
    bool LoadWatchOnly(const CScript &dest);
    
    int64_t nRelockTime = 0;
    bool Unlock(const SecureString& strWalletPassphrase);
    bool ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase, const SecureString& strNewWalletPassphrase);
    bool EncryptWallet(const SecureString& strWalletPassphrase);
    void GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) const EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    unsigned int ComputeTimeSmart(const CWalletTx& wtx) const;
    /**
     * Increment the next transaction order id
     * @return next transaction order id
     */
    int64_t IncOrderPosNext(WalletBatch *batch = nullptr) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    DBErrors ReorderTransactions();
    bool AccountMove(std::string strFrom, std::string strTo, CAmount nAmount, std::string strComment = "") EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    bool GetLabelDestination(CTxDestination &dest, const std::string& label, bool bForceNew = false);
    void MarkDirty();
    bool AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose=true);
    bool LoadToWallet(const CWalletTx& wtxIn);
    void TransactionAddedToMempool(const CTransactionRef& tx) override;
    void BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) override;
    void BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) override;
    bool AddToWalletIfInvolvingMe(const CTransactionRef& tx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate) EXCLUSIVE_LOCKS_REQUIRED(cs_wallet);
    int64_t RescanFromTime(int64_t startTime, const WalletRescanReserver& reserver, bool update);
    CBlockIndex* ScanForWalletTransactions(CBlockIndex* pindexStart, CBlockIndex* pindexStop, const WalletRescanReserver& reserver, bool fUpdate = false);
    void TransactionRemovedFromMempool(const CTransactionRef &ptx) override;
    void ReacceptWalletTransactions();