Given the history, with the Great Seal Bug
https://en.m.wikipedia.org/wiki/The_Thing_(listening_device)
I would expect plenty of monitoring; it is cheap and easy.
But maybe I'm just expecting too much vigilance here.
On the other hand a fine, grounded mesh will protect just fine against such attacks. Even in windows. Look up IEMI shielding.
Now taking these two together I think that it is possible that the embassy had both shielding and detectors. Because the attacks may have happened outside the shielding, and the detectors were inside to detect bugs.
2. This Vanity Fair article believes it's mass hysteria: https://www.vanityfair.com/news/2019/01/the-real-story-behin...
https://en.m.wikipedia.org/wiki/The_Thing_(listening_device)
Re: a mesh in the windows, given that we can’t even shield microwaves, I’m seriously doubting such a weak faraday mesh would be effective. But I don’t really know what the attenuation model would be.
Perhaps my assessment is overly pessimistic, but I think your assessment is overly optimistic.
I disagree about the shielding of microwaves because the shielding is obviously very effective. If it weren't so, we'd feel physical discomfort with our face less than a meter from the magnetron.
For the properites of shielded windows, I refer to "Shielding Effectiveness and HPM Vulnerability of Energy-saving Windows and Window Panes"[0]. The three panes they measured range from 15 dB to 35 dB attenuation. Now scaling an attack by 15 dB is not generally easy. It may mean you have to reduce the distance and operate from a van instead of a flat for example. By 35 dB we're talking about three orders of magnitude which makes scaling impossible because it'd cook the whole neighborhood.
[0] https://www.researchgate.net/publication/324950137_Shielding...