I want to correct myself. The genetic history of unsampled Southern regions will be in most likelihood different from North.
In modern Armenia ( North) there is no discontinuity at 1200bc. While in South there is an obvious discontinuity at 1200bc with the spread of Grooved ware ( other name Nairi ware ).
There is little doubt that Mushki came from North. While the exact origin of Urumu is hard to pinpoint but they settled both West and East of lake Van.
My opinion is that Urumu tribe created the Urartu kingdom and was it's ruling dinasty. The exonym Armenia might be derived from Urumu/Aramali.
While Mushki ultimately moved to west and settled in Anatolia around Kesaria ( ancient Mazhaka ) . They probably mixed with Phrygians or even reached elite positions in Phrygia. That's why Near Eastern people started to call Phrygia as Mushki.
Other tribes were also active in Early Iron Age. A Nairi confederation formed under the leadership of Diaukhi/ Dayene. Directed against Assyrian empire.
Another important kingdom was the Hubushkia-Nairi of a certain Kakia. It was in 9th century BC. It's interesting that Urartu elite himself was considering themselves as kings of Nairi. Though the name Biaina was much more important for them.
In sum we might see a serious migration of Northern genetic profile to South in 1200bc. But also to West. An indirect evidence of that are the Bronze Age samples from Malatya. They do not plot exactly with modern Armenians. Which means that at some point after EBA we must see a change of population in Malatya. And I suspect it occured both in 1200bc and Urartu period also.