The decision was made according to the report after the Commission became aware of the group's existence last month and deemed the risk of compromise too high. While there is no evidence yet that communication has actually been intercepted, the threat situation has escalated. Just recently, a private phone call between a journalist and an EU official was intercepted and published. Insiders also report sophisticated phishing attempts. These were intended to trick cabinet members into revealing their Signal PIN codes, thus causing them to lose control of their accounts.

looks like theyre concerned about targeted phishing attacks and organizations being unable to control user accounts from the top down (and thus read their communications) in order to reinstate and do damage control surrounding a negligent user after an attack. ultimately the user is getting tricked into revealing their password, so... human element. perhaps matrix would be best for large organizations like this, for individuals however simplex chat has no identifier tied to the account and in order to compromise a chat theyd need direct access to the computer or the simplex database export afaik, but all programs are vulnerable in that way.

https://www.heise.de/en/news/Signal-Takes-threat-of-targeted-phishing-attacks-very-seriously-11205329.html

Same same on both aspects.

Plus, I think I have a crush on Meredith.

The decision was made according to the report after the Commission became aware of the group's existence last month and deemed the risk of compromise too high. While there is no evidence yet that communication has actually been intercepted, the threat situation has escalated.

US American servers.

The article did reference the Signal chat leak. It's also worth noting that Signal is secure, its just also available to the public and not designed for officials only. Cryptography is useless if the device itself is compromised or if someone is added to a chat. I assume they're making people use an internal system that only officials have accounts on. That way you can accidentally add a journalist or impersonator to the chat.

While Signal is still considered one of the most secure options, security ends when the end device itself is compromised. If an attacker gains control of the smartphone, even the best end-to-end encryption is of little use: chats and images can then be read directly on the device. However, Herpig emphasizes that there are currently few better alternatives to encrypted messengers like Signal or Threema.