This is a great move for OpenAI and one that should worry Anthropic. Bedrock was the only way I could use foundation models for a while given AWS lock-in and security requirements.
Claude is already available as both a pass-through to Anthropic's servers from AWS and in Bedrock. https://aws.amazon.com/claude-platform/ I imagine they're not thrilled that their first mover advantage has gone now, but they'll have seen it coming a mile off.