--- reftex-global.el	2022-01-21 09:49:22.089091968 -0800
+++ reftex-global-patched.el	2022-01-21 09:51:20.594179163 -0800
@@ -183,7 +183,7 @@
     (if (string= from "") (setq from default))
     (unless to
       (setq to (read-string (format "Replace label %s with: "
-                                    from))))
+                                    from) from)))
     (reftex-query-replace-document
      (concat "{" (regexp-quote from) "}")
      (format "{%s}" to))))