This answer looks eerily similar to the llama-3-sonar-large-32k-online model by Perplexity on labs.perplexity.ai
This is searchable now.
Claude seems unlikely (unless it's a potential 3.5 rather than 4), since Claude-3 cutoff was 8-2023, so 11-2023 seems too soon after for next gen model.
The other candidate would be Gemini, which has an early 2023 cutoff, similar to that of GPT-4.