Frédéric Dubut from Bing said on Twitter that if you noindex your sitemap it still won't prevent Bing or other search engines from discovering your URLs (noindex on sitemaps do not work that way). This is similar to Google and how other search engines work.
Frédéric said "NOINDEX'ing your sitemap has no negative impact on our ability to discover your URLs (assuming we can *crawl* it). And there's no point in having it showing up in the SERP - nothing bad but your job is not to send searchers to your sitemap, is it?"
This jives with how Google works as well and what John Mueller from Google said recently and also last year:
Here are those tweets:
NOINDEX'ing your sitemap has no negative impact on our ability to discover your URLs (assuming we can *crawl* it). And there's no point in having it showing up in the SERP - nothing bad but your job is not to send searchers to your sitemap, is it? 🙂 So basically, what John said.
— Frédéric Dubut (@CoperniX) April 22, 2020
So do not use this as a strategy for hiding content from search engines, it won't work.
Forum discussion at Twitter.
