Ehhh I do not really like this idea.
I have ignored users before, but when I see others' comments back to them I decide that I might want to take them out of cherem and actually participate in the discussion.
If iI see it going nowhere, then I might put them back into my ignored user list.
Other than that I don't think we should penalize ourselves from seeing other people's sometimes insightful responses to the aforementioned ignored user.