What gets one a suspension in the majority of cases is disruption. It doesn't particularly matter what you do to be disruptive; if you found some way to be massively, repeatedly disruptive by retagging posts, you'll get suspended. While the action which eventually caused the suspension was technically "retagging" it would hardly be fair to say that means one can be suspended "for retagging posts".
So can you be suspended for being "too controversial" is the wrong question; it's not really the disagreement that's the problem, it's the problems it does (or doesn't) cause that matter. "Too controversial" for some is trolling/stubbornly sticking to an issue to others. If you consistently and insistently post opinions/arguments with the intent/effect of being disruptive it's certainly possible to be suspended for it.
Intent and disruption are the big factors (to me); both are generally required for a suspension. Sometimes people cause a big disruption once or twice on accident; I give them a nudge as to why whatever they did was problematic, and if they don't do it again it's rarely a suspendable offense. With no intent, it's not that bad. When one causes disruption on purpose, either by clearly intending to attack others or by going against previous warnings from the community/moderators, then a suspension becomes more likely.
Don't beat a dead horse; especially on small communities when that one guy is always bringing up that thing no one agrees with him on, discussion turns toxic. Just because Meta is for discussion doesn't mean people are allowed to be deliberately toxic to others. It's the sort of thing there's really no firm rules on, but if it becomes a problem a moderator may have to step in.
Note that as was brought up in the comments, Meta Stack Overflow is a bit of an exception; you can be automatically question banned on MSO by posting a large number of downvoted questions (or a number of largely downvoted questions) with few/no positively scoring questions. But honestly I wouldn't consider exclusively posting highly downvoted posts to be * controversial*, that's more just universally bad, controversy usually implies there are actually two (sizable) sides to the matter.