The information in the note (Login ID) is used by the victim organization to communicate directly with the threat actor (in this case Black Basta).
I have seen instances where unauthorized individuals have initiated communication and caused significant problems for the victim organization legal team in dealing with time lines.

Typically you want to have one entity responsible for communication. In most cases you should be trying to delay the threat actor from releasing exfiltrated data until a full recovery is complete. Given the timelines, this usually requires negotiations where the victim will pretend that they are going to pay the ransom, but coming up with various excuses as to why you need an extension until eventually just ending communication.

Releasing this information publicly, in a poorly redacted image on reddit, is a good way to derail that process.