Many newspapers today report that the Bombardier rakes may be flagged off on 26th January. They have not yet got the final clearances, so this date too cannot be considered as a confirmed date. Remember, 15th August 2014 too was announced as a possible date for flagging off. But due to the requirement of coupler force trials it was indefinitely postponed.
So, unless there is any official communication from the railways in the form of advertisement or press release, 26th January cannot be considered as a confirmed date of inauguration.