DOC-3526: Add TinyMCE AI bug fix release note for chat updating empty documents (TINY-14393)

Author: kemister85

modules/ROOT/pages/8.7.0-release-notes.adoc

@@ -28,6 +28,19 @@ include::partial$misc/admon-releasenotes-for-stable.adoc[]
 
 The following premium plugin updates were released alongside {productname} {release-version}.
 
+=== TinyMCE AI
+
+The {productname} {release-version} release includes an accompanying release of the **TinyMCE AI** premium plugin.
+
+**TinyMCE AI** includes the following fix.
+
+==== Chat can now update an empty document
+// #TINY-14393
+
+Previously, submitting a Chat prompt with empty editor content updated only the chat response and not the document. The editor now sends an empty paragraph to the model when the content is empty, so changes are applied directly to the document.
+
+For information on the **TinyMCE AI** plugin, see: xref:tinymceai.adoc[TinyMCE AI].
+
 // === <Premium plugin name 1> <Premium plugin name 1 version>
 
 // The {productname} {release-version} release includes an accompanying release of the **<Premium plugin name 1>** premium plugin.