I am guessing you are thinking that ansible uses the very old Linux
kernel model where a release X.Y is denoted as development if Y is odd
and production if it is even. I do not think Ansible has ever followed
that model and the Linux kernel hasn't followed it in 6 years.
The docs side is somewhat new so some pages in Google might be pointed towards older versions. Making sure the URL is set to latest will always be the latest version while setting to devel will point to the current devel version.