Most forces of the alliance base, even Jaina, are tagged as Silver covenant (though Jaina and other mages maintain their Kirin Tor title). I'm assuming this is because the new factions, Sunreaver onslaught and Kirin Tor offensive, haven't been implemented yet.
But most forces in the alliance beachead are Silver covenant NPC's, moreso, they are the NPC's that used to be in Dalaran/Argent Tournament/Hrotgar's Landing.
Are they just placeholders, will they get relocated to the new faction, mantain that faction,or will the silver covenant merge with the kirin tor offensive as the war effort progresses? That last one comes from the idea that maybe the Silver covenant under Jaina prepares the base for the arrival of the Kirin tor Offensive proper.
PS: Things are the same horde-side, but is less noticeable since they are pretty much all blood elves but for a few npc's (there's a plague consultant y'all!)