There are a lot of benefits to unguarded communication: you can move faster, you can open up your tentative thoughts to friendly consideration and criticism, you don't have the mental or process overhead of needing to get every statement as perfect as possible. You might say something that you don't mean to, but in a friendly environment you can correct yourself or accept someone elses correction.

Despite these benefits, it seems to me that things generally move in the more guarded direction, at least publically, as they become more successful. I've given this example a lot, but compare GiveWell's early blog posts to their current ones: their current posts are far more formal and carefully phrased, they now have proofreading, they post much less often, and they only post when they have something especially important to say. Similarly the comments on the posts used to be a lot more "lively", with more back and forth over speculative ideas. This all makes sense: GiveWell now has a strong reputation, and many more people are reading their writing now.

I've noticed this at the individual level as well. For example, I was talking to a friend who works at the Open Philanthropy Project at an EA meetup, and the way they talked about EA things seemed much more measured and careful than it was several years ago. I asked them about it, and while I don't remember their response exactly I think it was something like (a) wanting to present a good impression for OpenPhil even though they were there in their personal capacity and not as an explicit representative, and (b) needing to be careful about what was public information and what they only knew through their employment.

This last bit, taking care not to accidentally leak confidential information, seems unavoidable, and the general increase in guardedness seems like a natural consequence of becoming more successful and the world in general not being very good about handling transparency. But overall the increase in guardedness I've seen in the EA community makes me sad: as people or organizations become more knowledgeable and get various forms of influence they tend to communicate more minimally [1] which means we hear less of the voices that are most informative. I'm also worried that the kind of world-visible public discussions about how to do the most good that were key to the early development of EA are also important for EA staying on track in the long term. I don't know how to make things better, though.

[1] This also includes people being busier and so having a higher opportunity cost for discussion and information sharing. But this is multiplied by the extra communication burden of needing to be very careful in what you do say, and that makes it very easy for the benefit to fall below the cost.