They've been releasing their models 2 weeks after the first announcement. I doubt Google is timing their GA against Anthropic unless they had knowledge of when exactly Anthropic was releasing theirs.

Also, I've been using Carbon vs Opus 5.5 and Carbon is a great model. Haven't seen any hallucinations. Argon was well known to be a worst programming model than Opus via benchmarks, so you and influencers broadcasting a well kept secret.