Block bindings for a field that used to be a shortcode

A shortcode from 2016 rendering a meta field, replaced by a binding on a core paragraph.

<!-- wp:paragraph {
  "metadata": {
    "bindings": {
      "content": {
        "source": "core/post-meta",
        "args": { "key": "product_sku" }
      }
    }
  }
} -->
<p></p>
<!-- /wp:paragraph -->

The meta key must be registered with show_in_rest and a sanitisation callback or the binding renders nothing, silently, which is the first thing to check. What this removes is a shortcode that was invisible in the editor — an author saw [sku] and now sees the value.