In fact congress did delay it from its schedule 2015 change. It was meant to be delayed until 2017 after Obama was gone. Typically Obama is acting unilaterally.
From Aug 2015.
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Congress used its budget power to block Commerce from giving up the Icann contract during 2015, which should mean a two-year renewal into the next presidency. The Obama administration ignored that timetable and set the new date of July 2016 to give up control. Meanwhile, no alternative has emerged to protect the open Internet.
http://www.wsj.com/articles/ted-cruzs-fight-to-protect-the-open-internet-1438551531