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.
{
    UniValue ret(UniValue::VOBJ);
    if (verbose) {
        ret.pushKV("name", data.name);
    }
    ret.pushKV("purpose", data.purpose);
    return ret;
}
UniValue getaddressinfo(const JSONRPCRequest& request)
{
    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() != 1) {
        throw std::runtime_error(
            "getaddressinfo \"address\"\n"
            "\nReturn information about the given bitcoin address. Some information requires the address\n"
            "to be in the wallet.\n"
            "\nArguments:\n"
            "1. \"address\"                    (string, required) The bitcoin address to get the information of.\n"
            "\nResult:\n"
            "{\n"
            "  \"address\" : \"address\",        (string) The bitcoin address validated\n"
            "  \"scriptPubKey\" : \"hex\",       (string) The hex encoded scriptPubKey generated by the address\n"
            "  \"ismine\" : true|false,        (boolean) If the address is yours or not\n"
            "  \"iswatchonly\" : true|false,   (boolean) If the address is watchonly\n"