I am preparing a large thread about the post Urartian Armenia (RoA), especially the shift from Etiuni to Armenian genetic profile. I started to look closer to some relevant samples. For instance the two samples labeled Sarukhan_unknown.
They are supposedly from 72 BC but their autosomes are typically Lchashen Metsamorian (1500-800/600bc). This is the main reason why they are labeled as "unknown". Because their genetic age do not much their supposedly radiocarbon age.
"Context: Date(s) from same site (I20437)"
This means that they are dated based on the archaeologic context and the radiocarbon dating of I20437 which is indeed from Artashessid period. Both by genes and radiocarbon.
In most likelihood their true age is LBA/EIA. Their Y DNA is also typical to that period. I2 and E-M84. This means that at this point the last sample after which we don't see anymore the typical Etiuni/Lchashen profile is dated at 603BC. A sample from Karmir Blur. This date correspond to the end of Urartu. Offcourse we have a gap between 600 and 400bc which needs to be filled. We also should keep in mind that radiocarbon dating will never give the necessary precision. But overall we can assume that it's during the end of Urartian kingdom that some important genetic changes occured in RoA.