on the occasion of the 80th anniversary of the founding of the North Korean Air Force, during Kim Jong-un's visit to an air base he made what I think was an important announcement, reported in the long article published on KCNA in English, the important sentence verbatim states:
"Noting that the Air Force will be given new strategic military assets and entrusted with a new important duty, he said that the expectations of the Party and the country for the Air Force which will play a role in the exercise of the nuclear war deterrent are very great, and that the Air Force should resolutely repulse and control all sorts of espionage acts and possible military provocations of the enemies to encroach upon the sovereign airspace of the DPRK with the overwhelming spiritual strength and offensive spirit."
These words lead me to believe that there will soon be innovations in air defense, beyond what we saw in the photos.
They could be new anti-aircraft missiles, but I think he was referring to an upgrade in manned aircraft, with the arrival of new models.