I’d take anything from that JW/JW apologist blog with a huge bag of salt. Most of the analysis is not incorrect though, they did go underground, they continue receiving directions from the US, and they did move to covert channels. They do attract the dispossessed, anti-government type and pedophiles into their midst with the messaging.
All-in-all they do operate like a terrorist cell, it wouldn’t surprise me that at least some of the congregations in such situation have been infiltrated by eg CIA operatives and planning on some anti-government activity.
Note too that there is a translational gap, anti-government/terrorist activity in Russia includes the messages about Armageddon they’re spreading to which they are terrorizing their believers and children with, which is the reason they were convicted under Russian law. It is a cultural/translational difference where in the west we’ve been accustomed to various religious and thus take that messaging not too seriously, Russians will take any religious messaging pretty serious since the Eastern Orthodox eschatology doesn’t shy away from it either, they have rather graphic descriptions of the end of times as well, so any religious group that comes by and says, yeah, we “know” it will be “soon” and here is a picture of what it looks like, is basically playing into life-long religious fears.