I not so sure what is ‘proper’?
While I understand your/the concerns regarding user experience and forum support I’m not sure it is in the spirit of Manjaro. I realise that the kernel is somewhat special but often/in general Manjaro rolls with beta, release candidate, and cutting (not bleeding) edge software. For example, Firefox-beta releases are the norm, Wine is currently ‘rc’, etc. It does not aim for stability over all else.
If I have it correct MSM does not notify users about rc kernel versions by default but only when they are properly released. That means they have been signed off on by the kernel developers as stable enough for community distribution. Issues will be spotted with wider use and rolling distro’s will likely be first to notice. That’s part of the way the kernel develops.
Manjaro allows the possibility to avoid the newer kernels (unlike say Firefox or Wine) and that is a great strength. But I believe it is also a strength for the distro to be rolling with the newest kernel by default. If there are issues regarding the stability of released kernels then that should be taken up, upstream.
So I am happy with the current situation. Making users more aware of this situation is however something that I would fully support.
Just my two cents.