Do they think Russian intel workers can’t read English?

Yes.

I forget the source, but I remember watching a video of a Russian and a Ukrainian debating something using Russian, well before the current military operations. Ukrainian called them out for having to have the debate in Russian because "I bet you can't even speak any English". Russian guy switched to near perfect English, and Ukrainian guy struggled for about five minutes in very broken English before switching back to Russian. It was pretty embarassing.