Interesting that you interpreted a dislike of something as "bursting their bubble". Have you considered alternative explanations that are actually correct?
There are leftists of many stripes in the fediverse, if a discussion on Lemmy.ml ruffles ones feathers because of the predominant politics of their users then yes, it sounds like someone's precious bubble was burst.
There are myriad reasons why someone could dislike a discussion without that discussion being new to them, or correct, or particularly notable in any other aspect.