VS Code doesn't show predefined launch.json files

Question

I'm following This VSCode MinGW guide.Everything works fine until the debugging part, where I need to choose Run > Add Configuration... and then choose C++ (GDB/LLDB). After that, the guise writes that i should see a dropdown of predefined configurations, but that does not happen to me. Instead I get a launch.json file with no configurations. Inside launch.json i can use the Add Configuration.. button to create a C/C++:(gdb) Launch configuration so I tried the following:

 {
        "name": "(gdb) Launch",
        "type": "cppdbg",
        "request": "launch",
        "program": "${workspaceFolder}/main.exe",
        "args": [],
        "stopAtEntry": true,
        "cwd": "${fileDirname}",
        "environment": [],
        "externalConsole": false,
        "MIMode": "gdb",
        "miDebuggerPath": "C:\\MinGW\\bin\\g++.exe",
        "setupCommands": [
            {
                "description": "Enable pretty-printing for gdb",
                "text": "-enable-pretty-printing",
                "ignoreFailures": true
            },
            {
                "description":  "Set Disassembly Flavor to Intel",
                "text": "-gdb-set disassembly-flavor intel",
                "ignoreFailures": true
            }
        ]
    }

This way when I start debugging, all I see is that it's loading, and I can't use debugging. For the task.json file it worked fine.

Edit: I found a working configuration, that would be:

{
  "version": "0.2.0",
  "configurations": [
{
  "name": "g++.exe - Build and debug active file",
  "type": "cppdbg",
  "request": "launch",
  "program": "${fileDirname}\\${fileBasenameNoExtension}.exe",
  "args": [],
  "stopAtEntry": false,
  "cwd": "${fileDirname}",
  "environment": [],
  "externalConsole": false,
  "MIMode": "gdb",
  "miDebuggerPath": "C:\\msys64\\mingw64\\bin\\gdb.exe",
  "setupCommands": [
    {
      "description": "Enable pretty-printing for gdb",
      "text": "-enable-pretty-printing",
      "ignoreFailures": true
    }
  ],
  "preLaunchTask": "C/C++: g++.exe build active file"
    }
  ]
}

but, i still don't understand why this one works, and the upper one doesn't. (changing the program configuration in the wrong launch.json file to match the new one doesnt have any effect)