That only happens on anything we have here when you copy off the glass, anything in the ADF does not get that screen at all.
Copies from the glass are just assumed to be multipage and odd sized so that happens, where the ADF knows when there is no paper the job is done.
If it is happening through the feeder I am afraid you would need to contact Xerox to find out why yours behaves differently. If you are doing scans on the glass, the answer is "You can't disable that screen"