This situation is very different from the Streisand effect. In the Streisand effect a single party is trying silence everyone else. Here everyone is trying to silence you.
They are nearly opposite situations. A minority trying to silence a majority vs a majority trying to silence a minority.
Downvoting is (afaik) for not meeting the norms of polite / intelligent discourse as opposed to "we disagree with your opinion". There are opinions which if expressed breach out taboos - the usual range if racism sexism etc - but this is certainly not the case here.
So no, I think downvotes for a comment that is polite, intelligent, on topic and part of a discussion was the wrong use of downvotes.
I still don't agree with it of course :-) User choice is a bugger on cloud services especially where they are shelling out to run the pygments lexer.
On top of which is probably the interesting issue that there is no longer a binary on/off for most features. AB testing, feature toggles, stayed rollouts all mean we never quite know which version of a service we are running.
But those cultural norms are also only strong in a small subset of users. Plenty of people vote to agree or disagree, and this was acknowledged by pg. "Don't down-vote to disagree" is something brought over from Reddit and there is some strong resistance to it in some long term users (here longer than six years).
They are nearly opposite situations. A minority trying to silence a majority vs a majority trying to silence a minority.
In both situations the majority wins.