This Reddit thread reports a change to posting user reviews. Now you have to explicitly enable an option for other people to comment on it. I did a quick login to my Steam account and confirmed that’s correct, and the option is unchecked by default.
Most of the people in that thread seem to be (predictably) pissed, but I think this is actually quite good, if only to keep the usual suspects from brigading reviews they don’t agree with.
And yeah, that’s a tiny positive step on a platform that has a bunch of bigger issues. Take what you can get, etc.