Can I replicate the InstantSearch queryRuleCustomData widget to display a banner in Autocomplete?

Although the queryRuleCustomData widget is not specifically available in Autocomplete, the custom data used by this widget to display a banner is available in the JSON response when a corresponding Rule is triggered.

In this sample response to a query that has triggered a Rule to return custom data, the banner image is available by accessing the userData attribute ( userData[0].image specifically for the banner).

{
  "hits": [],
  "userData": [
    {
      "image": "https://YOURIMAGEDOMAIN.YOURIMAGE.jpg",
      "title": "YOUR TITLE"
    }
  ],
  "nbHits": 0,

...
}

You can customize Autocomplete to display/use this image.  This guide to Populating Autocomplete with Sources may be helpful in getting started with your customization. [Note: Customization and implementation guidance is out-of-scope for the Support Team.]