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.
{
    std::shared_ptr<CWallet> const wallet = GetWalletForJSONRPCRequest(request);
    CWallet* const pwallet = wallet.get();
    if (!EnsureWalletIsAvailable(pwallet, request.fHelp)) {
        return NullUniValue;
    }
    if (request.fHelp || request.params.size() != 0)
        throw std::runtime_error(
            "listaddressgroupings\n"
            "\nLists groups of addresses which have had their common ownership\n"
            "made public by common use as inputs or as the resulting change\n"
            "in past transactions\n"
            "\nResult:\n"
            "[\n"
            "  [\n"
            "    [\n"
            "      \"address\",            (string) The bitcoin address\n"
            "      amount,                 (numeric) The amount in " + CURRENCY_UNIT + "\n"
            "      \"label\"               (string, optional) The label\n"
            "    ]\n"
            "    ,...\n"
            "  ]\n"
            "  ,...\n"