...by recording the conversation so it can be uploaded to the server that does the recognition, because nobody is doing this kind of processing client-side.
Just like the idea that "streaming" is somehow different than "downloading", the commonly-repeated claims that this kind of technology is only "processing" without mentioning where the data is processed is a carefully constructed lie designed to frame the discussion.
The use of propaganda to confuse how their product works suggests that Facebook (et al) knows there would be resistance if they offered the same features plainly. In my opinion this should count as mens rea.