This is very interesting, thanks for posting.

According to completedns.com, instant-stresser.com has been using Cloudflare on and off for almost 8 years, and continuously for the last 3 years. It's also the 2nd result on Google for searching "free stresser". It seems impossible that this site hasn't been reported to Cloudflare by now, indicating that they have made the decision to continue protecting it. Very bad.

I haven't checked the other sites you mentioned, but if this pattern holds, it definitely changes my perspective on Cloudflare.