As I commented on iNaturalist, I personally believe it's not introduced, but this areal is the eastern border of the natural distribution. With the local warming due to the climate change being especially high in Russia (https://assets.science.nasa.gov/content/...al_gis_2022.png), there's probably also a tendency of enhancing the distribution towards the northeast, probably for many decades now.
So old sources not stating A. albipennis for this part of Russia could be due to 1) underrecording, since the species lives only in certain habitats and Russia is large with a lot of nature and 2) the species being much less present in the 1800s and 1900s.

I would expect the same trend for Chelidurella acanthopygia.