If you do not want the delimliter and year only to be specifically matched then make that part of the RE pattern a non-capturing group.
See example.
#include <Array.au3>
Local $sString = StringRegExpReplace(FileRead(@ScriptFullPath), "(?is)^.*#cs\R|\R?#ce.*$", "") ; ClipGet()
ConsoleWrite($sString & @CRLF)
$a = StringRegExp($sString, "((?:[0-9]{1,2}[\h\-\\/.]{0,3}){2,3})", 3)
_ArrayDisplay($a)
; Modified $aDelim from Post#1
$aDelim = StringRegExp($sString, '(\d{1,2}\s?[\055|\056|\057|\134]\s?\d{1,2}(?:\s?[\055|\056|\057|\134]\s?\d{2,4})?)', 3)
; Note addition of "?:" in the RegExp pattern in the line above here~~~~~~~~~^
_ArrayDisplay($aDelim, "$aDelim")
; Data for variable $sString - Copied from Post#1
#cs
02 / 9 \ 16 – test
07 - 9 . 16 – test
09/9/16 – test
14\9\16 – test
16-9-16 – test
21.9.16 – test
23/9 – test
28\9 – test
#ce