Frédéric Dubut from Bing said that its search engine never supported the noindex in a robots.txt file before. So nothing is going to be changing with Bing on that front. While we heard Google did unofficially support it and will stop supporting it on September 1st.
Frédéric Dubut wrote on Twitter "The undocumented noindex directive never worked for Bing so this will align behavior across the two engines. NOINDEX meta tag or HTTP header, 404/410 return codes are all fine ways to remove your content from Bing.
I asked him this to confirm prior and he said nope, not going to support what is not supported:
We don't support it. And logically it will not change. 🙂
— Frédéric Dubut (@CoperniX) July 2, 2019
The undocumented noindex directive never worked for @Bing so this will align behavior across the two engines. NOINDEX meta tag or HTTP header, 404/410 return codes are all fine ways to remove your content from @Bing. #SEO #TechnicalSEO https://t.co/ukKhfRPWzO
— Frédéric Dubut (@CoperniX) July 2, 2019
Again, another reason why Google made the right call by not supporting it?
Forum discussion at Twitter.
