Why Is trackEvent Working in Web SDK Implementation?

I recently implemented a custom script for Adobe Target using the trackEvent API, despite using the Web SDK for my setup. Surprisingly, the script is working, and the trackEvent is successfully passing parameters to Adobe Target. I would like to understand why this is happening, given that sendEvent is the recommended method for Web SDK.

Here is the script I used:

<script>
const osTheme = window.matchMedia("(prefers-color-scheme: dark)");
if (osTheme.matches) {
  adobe.target.trackEvent({
      "mbox": "themePreference",
      "params": {
          "userTheme": "dark"
      }
  });
} else {
  adobe.target.trackEvent({
      "mbox": "themePreference",
      "params": {
          "userTheme": "light"
      }
  });
}  
</script>

What I Observed:

• The event is being successfully logged in Adobe Target.
• The userTheme parameter is being sent and correctly recognized by Target.
• Debugging data confirms that the event is processed correctly:

{
  "eventType": "decisioning.propositionDisplay",
  "_experience": {
    "decisioning": {
      "propositions": [
        {"scope": "themePreference"}
      ],
      "propositionEventType": {
        "display": 1
      }
    }
  },
  "data": {
    "__adobe": {
      "target": {
        "userTheme": "dark"
      }
    }
  }
}

My Questions:

1. Is trackEvent officially supported in the Web SDK, or is this behavior due to some fallback compatibility mechanism?
2. Could this be a legacy feature of Adobe Target still supported for certain implementations?
3. Should I refactor my code to use sendEvent for long-term compatibility?
4. Is there any documentation that explains why trackEvent works under these circumstances?

Additional Information:

• The mbox themePreference is already configured in Adobe Target.
• The data passed (e.g., "userTheme": "dark") is visible in debugging tools.
• I’m using Adobe Launch to deploy the Web SDK.

Thank you for your assistance in clarifying this behavior and guiding me on the best practices moving forward!