I had heard that Russia had moved 4 to 6 more aircraft to Armenia about a month ago, roughly doubling the aircraft that they had stationed there.
Russia has rattled a lot of sabers at Turkey since they shot down that Russian jet in November - brandishing weapons on ships sailing through Istanbul, laying down punishing economic sanctions, publicizing Erdogan’s corruption in profiting from oil smuggled from Syria and Iraq, alluding to the possibility of supporting a Kurdish uprising within Turkey, and increasing military forces around Turkey (such as more jets in Armenia, and the S-400 air defense system in Northern Syria).
I think that Turkey knows that if they go head to head with the Russians, they will get hit from many angles at once. The Kurds have never had such deterrence against Turkish attacks before.
The Turkish military must be chewing their teeth in frustration at the results of Erdogan’s adventures.
Maybe some of the reports of increased air traffic at Erebuni are touch-downs/refueling of aircraft en-route to Syria bases.
A side note...I was surprised Russia flew the "White Swan" on bombing flights over Syria. And the Swan flew all the way from the Kola Peninsula.