Index: assets/css/editor-style-block-rtl.css
===================================================================
--- assets/css/editor-style-block-rtl.css	(revision 47512)
+++ assets/css/editor-style-block-rtl.css	(working copy)
@@ -899,7 +899,6 @@
 	letter-spacing: 0.0333em;
 	line-height: 1.25;
 	padding: 1.1em 1.44em;
-	text-transform: uppercase;
 }
 
 .editor-styles-wrapper .wp-block-button .wp-block-button__link.mce-content-body {
Index: assets/css/editor-style-block.css
===================================================================
--- assets/css/editor-style-block.css	(revision 47512)
+++ assets/css/editor-style-block.css	(working copy)
@@ -899,7 +899,6 @@
 	letter-spacing: 0.0333em;
 	line-height: 1.25;
 	padding: 1.1em 1.44em;
-	text-transform: uppercase;
 }
 
 .editor-styles-wrapper .wp-block-button .wp-block-button__link.mce-content-body {
Index: assets/css/editor-style-classic-rtl.css
===================================================================
--- assets/css/editor-style-classic-rtl.css	(revision 47512)
+++ assets/css/editor-style-classic-rtl.css	(working copy)
@@ -527,7 +527,6 @@
 	padding: 1.1em 1.44em;
 	text-align: center;
 	text-decoration: none;
-	text-transform: uppercase;
 }
 
 body#tinymce.wp-editor.content button:focus,
Index: assets/css/editor-style-classic.css
===================================================================
--- assets/css/editor-style-classic.css	(revision 47512)
+++ assets/css/editor-style-classic.css	(working copy)
@@ -531,7 +531,6 @@
 	padding: 1.1em 1.44em;
 	text-align: center;
 	text-decoration: none;
-	text-transform: uppercase;
 }
 
 body#tinymce.wp-editor.content button:focus,
Index: style-rtl.css
===================================================================
--- style-rtl.css	(revision 47512)
+++ style-rtl.css	(working copy)
@@ -844,7 +844,6 @@
 	padding: 1.1em 1.44em;
 	text-align: center;
 	text-decoration: none;
-	text-transform: uppercase;
 	transition: opacity 0.15s linear;
 }
 
Index: style.css
===================================================================
--- style.css	(revision 47512)
+++ style.css	(working copy)
@@ -850,7 +850,6 @@
 	padding: 1.1em 1.44em;
 	text-align: center;
 	text-decoration: none;
-	text-transform: uppercase;
 	transition: opacity 0.15s linear;
 }