IIUC, any rogue high-level access employee could take over any account and post anything? Like make trump's account post "nuke inc @nk". I'm not sure if that's any more reassuring than just saying they got breached
“We detected what we believe to be a coordinated social engineering attack by people who successfully targeted some of our employees with access to internal systems and tools.”
I think it happened because everyone is working remotely and it is easier to perform social engineering attacks. Maybe this incident will have impact on their long term remote work plans.