It's natural to guideline out people (1) working the metaphorical refs with asides about voting and (2) posturing and, at the same time, implicitly disrespecting even the notion that some people might disagree with them. The former invites horrible meta conversations, the latter is uncivil and toxic.
But you don't want to go so far that people have to alter totally normal speech patterns in order to avoid some conversation tripwire that the guidelines set. If you do that, you get more pointless meta threads.
What I think you want is a guideline that says "no matter what, don't talk about how your comments are being voted, and if you must mention the feeling you have that what you're about to say is probably unpopular, do it in a nice way, and quickly". I don't know how to say that with any kind of concision.
(A lot of things would work as guidelines if they could capture the nuance of "this way of writing is fine if you assume the burden of being extra gracious about it, but not fine to do casually and thoughtlessly". But it's super hard to distill that sentiment into a guideline!)
How about something like:
Don't try to preempt reactions by starting "At the risk of being downvoted..." or "Unpopular opinion here..." State your case clearly and let your ideas stand or fall on their own.