This. Anthropic didn't really have a choice, at that point, short of killing its company and closing its doors ahead of time.

"Pentagon officials said the Defense Department is planning to keep using Anthropic's tools, regardless of the company's wishes."

NPR - Hegseth threatens to blacklist Anthropic over 'woke AI' concerns

Clearly the threat to go to Grok was just a bluster, which says volumes about what the admin thinks of Grok vs Claude.