Anyone should be able to freely express their opinion about any pin or manufacturer. This is called free speech. So I totally disagree with pinsiders that say we should always withold our opinions because it’s a new manufacturer or for whatever other reason.
However, there are socials norms to follow here so there is a time and place for this. For example, at one extreme, your criticism of a game is not welcome in a marketplace ad. If you feel the need to just rail on a game, then start your own thread. Also, pinball is hard, so give others a bit of a break sometimes.
There are a lot of grey areas here so not always clear on exact rules to follow but just generally be respectful to others. Ultimately though, pinsiders should be able to express their views somewhere on pinside. And be thankful that our countries allow us the option to express our opinions publicly.