I wouldn't think that outside sites that use the Disqus interface would be very happy that Disqus is also blocking their traffic by blacklisting. That takes revenue away from everyone.
Disqus is cutting its own throats by this practice.
No wonder they have lost half their traffic this year alone.
If you want to avoid headaches, avoid Disqus.
If your goal as a site owner is to make money, avoid the Disqus chat interface. Disqus will rob you of your revenue.