For a counter-argument to this: please check out muru's answer
I support showing everything on Meta.
The OP of the original MSE post makes a compelling point in my opinion, which is that important topics that are being discussed might go unnoticed if a post is hidden. Agreement or disagreement with the post is irrelevant, as both heavily downvoted posts and a heavily upvoted posts speak about the consensus on the topic - which may have also real-world (site) ripercussions.
Seeing the post in the first place is necessary in order to keep up with the consensus on new situations and with potential shifts in consensus on old situations. And obviously to form an opinon and express it, even when the number of votes has settled the overall consensus already.
Do we not need to be notified, when visiting Meta, that, say, taking edits that address grammar personally shouldn't be a thing because the relative question has been downvoted more than 8 times?
And, in general, are we allowed to further upvote a post that has 8 upvotes but not to further downvote a post that has 8 downvotes?
Furthermore Meta is a place of discussion, and silencing unpopular opinions (to me) kinda feels like censoship.
Addressing muru's answer, which makes a (per se) compelling and agreeable point about the low volume of questions that would be affected; while it's true that such a change wouldn't affect the site much, well... It wouldn't affect the site much.
According to muru's numbers, about one question in a hundread is currently hidden because of the amount of downvotes, so about a question in a hundread would suddenly resurface if this was sent live (for scale, one question voted -8 or less at most would suddendly pop up on the home page after the fact).
The low volume of questions that would be affected works against both arguments. Allowing this just wouldn't change too much.
So overall, in my opinion, even acknowledging the slimness of the chance of being able to see important topics being discussed, considering that, more compellingly at this point, as andrew.46 mentions in the comments it's desirable to "avoid the appearance of censorship", the scale is still tipped towards the positives.