It seems that Sukhoi SuperJet 100 got infected with the “delay” virus from its fetal friend B787. The delay of delivery might be an operational advantage for receiving air carriers as there is no current high demand for more aircraft, and practically till the time again for the summer schedule.
In fact, B787 is not only a friend of Sukhoi SuperJet 100, but a first cousin considering the fact that there is an agreement between Sukhoi and Boeing since 19th of December 2002. The affiliation with Boeing may be the actual source of infection.