I wrote to the contact point. And then, the page is updated now:
http://www.iro.umontreal.ca/~simardr/testu01/copyright.html
It says:
Copyright (c) 2002 Pierre L'Ecuyer, Universitϫ de Montrϫal.
Web address: http://www.iro.umontreal.ca/~lecuyer/
All rights reserved.
TestU01 is distributed under the GNU General Public License as
published by the Free Software Foundation, and is also available
under a commercial licence.
Any changes made to this package must be clearly identified as
such.
[...]
The source code distribution has not yet updated its copyright notice,
though.
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