SSMS is indicating that my OUTER APPLY has more columns than specified in the column list

Question

Here's my sample query in SQL Server 2017 for organizing the SQL normalized data to JSON data.

DECLARE @tbl_name 
    TABLE(
        id INT IDENTITY(1,1),
        u_id VARCHAR(30),
        f_name VARCHAR(50),
        l_name VARCHAR(50),
        dt_stamp DATETIME DEFAULT GETDATE()
        );

DECLARE @tbl_add
    TABLE(
        id INT IDENTITY(1,1),
        address VARCHAR(50),
        zip_code VARCHAR(5),
        u_id VARCHAR(30),
        dt_stamp DATETIME DEFAULT GETDATE()
        );

DECLARE @ID1 VARCHAR(30) = 'ID-1000-1001';
DECLARE @ID2 VARCHAR(30) = 'ID-1000-1002';
DECLARE @ID3 VARCHAR(30) = 'ID-1000-1003';

DECLARE @FN1 VARCHAR(50) = 'Juan';
DECLARE @FN2 VARCHAR(50) = 'Anna';
DECLARE @FN3 VARCHAR(50) = 'John';

DECLARE @LN1 VARCHAR(50) = 'Dela Cruz';
DECLARE @LN2 VARCHAR(50) = 'Smith';
DECLARE @LN3 VARCHAR(50) = 'Doe';

DECLARE @ADD1 VARCHAR(50) = 'Lucena City, Quezon, Ph';
DECLARE @ADD2 VARCHAR(50) = 'Quezon City, Metro Manila, Ph';
DECLARE @ADD3 VARCHAR(50) = 'Tayabas City, Quezon, Ph';

DECLARE @ZCODE1 VARCHAR(5) = '4301';
DECLARE @ZCODE2 VARCHAR(5) = '1100';
DECLARE @ZCODE3 VARCHAR(5) = '4327';

INSERT INTO
    @tbl_name
(
    u_id,
    f_name,
    l_name
)
VALUES
(
    @ID1,
    @FN1,
    @LN1
),
(
    @ID2,
    @FN2,
    @LN2
),
(
    @ID3,
    @FN3,
    @LN3
);

INSERT INTO
    @tbl_add
(
     address,
     zip_code,
     u_id
)
VALUES
(
    @ADD1,
    @ZCODE1,
    @ID1
),
(
    @ADD2,
    @ZCODE2,
    @ID2
),
(
    @ADD3,
    @ZCODE3,
    @ID3
);

SELECT
    tn.u_id AS [u_id],
    tn.f_name AS [name.f_name],
    tn.l_name AS [name.l_name],
    outer_apply.json_data AS [address_key]
FROM
    @tbl_name tn
OUTER APPLY
    (
        SELECT
            ta.address,
            ta.zip_code
        FROM
            @tbl_add ta
        WHERE
            ta.u_id = tn.u_id
        FOR JSON AUTO
    ) outer_apply(json_data)
FOR JSON PATH;

Surprisingly, the query is working fine after I executed it as shown in the image below.

With beautified JSON data output:

[
  {
    "u_id": "ID-1000-1001",
    "name": {
      "f_name": "Juan",
      "l_name": "Dela Cruz"
    },
    "address_key": [
      {
        "address": "Lucena City, Quezon, Ph",
        "zip_code": "4301"
      }
    ]
  },
  {
    "u_id": "ID-1000-1002",
    "name": {
      "f_name": "Anna",
      "l_name": "Smith"
    },
    "address_key": [
      {
        "address": "Quezon City, Metro Manila, Ph",
        "zip_code": "1100"
      }
    ]
  },
  {
    "u_id": "ID-1000-1003",
    "name": {
      "f_name": "John",
      "l_name": "Doe"
    },
    "address_key": [
      {
        "address": "Tayabas City, Quezon, Ph",
        "zip_code": "4327"
      }
    ]
  }
]

But I noticed an obvious syntax error that I am worried about:

'outer_apply' has more columns than specified in the column list

From this part of the query:

Moreover, I've been watching this relevant thread, but I ended up in confusion as to what to do next.

According to Martin Smith,

If you are actually getting this as a runtime error rather than an intellisense warning check that you are on the latest CU

However, when I execute SELECT @@VERSION, it prints:

Microsoft SQL Server 2017 (RTM) - 14.0.1000.169 (X64) Aug 22 2017 17:04:49 Copyright (C) 2017 Microsoft Corporation Standard Edition (64-bit) on Windows Server 2012 R2 Standard 6.3 (Build 9600: )

According to my senior colleague, it is because the compiler of the SQL Server I am using does not consider my query as a valid code (i.e., on the portion that indicates a syntax error).

I want to know what exactly causes the conflict in the syntax of the given query to eventually address it properly.

After reevaluating my case scenario, I needed address_key's value to be encoded as array since I have to process multiple entries per parent record (e.g., a person could have more than one address). Therefore, I need to monitor the syntax issue on this portion:

OUTER APPLY
    (
        SELECT
            ta.address,
            ta.zip_code
        FROM
            @tbl_add ta
        WHERE
            ta.u_id = tn.u_id
        FOR JSON AUTO -- here
    ) outer_apply(json_data)

The goal here is to ensure that it does not introduce exceptions, particularly in production.

Interestingly, the query works fine as well when I call it inside the SP (just added for additional idea about the case).