To anyone who has RSS and Cloudflare (or any CDN) WAF (firewall) on their website, don't block the access to your feeds.
The feed is usually just an XML file, most likely cached and the user still has to go through the firewall to access content from the link in the feed.
If you wholesale filter access to the website for anyone suspicious, most feed readers won't get an update as feed readers aren't actual browsers, just crawlers.