1) Why are they making such disclosures? Wouldn't they make it easier for hackers to get to them? For example, just for the sake of argument (know it's a bad argument because of math, large numbers, publicly visible to begin with but just put that aside) - if you provide the address hackers can begin trying to brute force it. But if you don't disclose it, a hacker would not even know where to start. It's like a robbery victim pointing hackers where to attack next.
The same way anyone can start brute-forcing satoshi's address or any of the Bitcoin top 10 rich wallets.
Think the question here is: why are they comfortable with hackers knowing such information.
It's in his tweet: "Transparency". When people know which address holds most of your reserves, they can suspect anytime it drains out.
Also, it's not hard to found that info after some blockchain analysis.