ICU-20975 update API Change Report for 66

- Compared against ICU4C 65.1
- no substantive change. Just dropped 'preview'
diff --git a/icu4c/APIChangeReport.html b/icu4c/APIChangeReport.html
index 5b767c7..a9fc025 100644
--- a/icu4c/APIChangeReport.html
+++ b/icu4c/APIChangeReport.html
@@ -5,12 +5,12 @@
 	-->
 <head>
 <META http-equiv="Content-Type" content="text/html; charset=utf-8">
-<title>ICU4C API Comparison: ICU 65 with ICU 66 (preview)</title>
+<title>ICU4C API Comparison: ICU 65 with ICU 66</title>
 <link type="text/css" href="icu4c.css" rel="stylesheet">
 </head>
 <body>
 <a name="#_top"></a>
-<h1>ICU4C API Comparison: ICU 65 with ICU 66 (preview)</h1>
+<h1>ICU4C API Comparison: ICU 65 with ICU 66</h1>
 <div id="toc">
 <ul>
 <li>
@@ -1501,7 +1501,7 @@
 <a href="#_top">(jump back to top)</a>
 <hr>
 <p>
-<i><font size="-1">Contents generated by StableAPI tool on Tue Dec 03 15:47:14 PST 2019<br>
+<i><font size="-1">Contents generated by StableAPI tool on Wed Feb 19 10:40:34 PST 2020<br>
         Copyright &copy; 2017 and later: Unicode, Inc. and others.<br>
         License &amp; terms of use: http://www.unicode.org/copyright.html
     </font></i>
diff --git a/icu4c/APIChangeReport.md b/icu4c/APIChangeReport.md
index 8b50fbe..5d9c116 100644
--- a/icu4c/APIChangeReport.md
+++ b/icu4c/APIChangeReport.md
@@ -5,7 +5,7 @@
  License & terms of use: http://www.unicode.org/copyright.html
 -->
 
-# ICU4C API Comparison: ICU 65 with ICU 66 (preview)
+# ICU4C API Comparison: ICU 65 with ICU 66
 
 > _Note_ Markdown format of this document is new for ICU 65.
 
@@ -520,7 +520,7 @@
 
 ## Colophon
 
-Contents generated by StableAPI tool on Tue Dec 03 15:19:41 PST 2019
+Contents generated by StableAPI tool on Wed Feb 19 10:40:39 PST 2020
 
 Copyright © 2019 and later: Unicode, Inc. and others.
 License & terms of use: http://www.unicode.org/copyright.html