Last Week in AI #244 - GPT-5.5 Instant, Grok 4.3, OpenAI vs Musk

Our 244th episode with a summary and discussion of last week's big AI news! Recorded on 05/08/2026 Hosted by Andrey Kurenkov and Jeremie Harris Feel free to email us your questions and feedback at andreyvkurenkov@gmail.com and/or hello@gladstone.ai Read out our text newsletter and comment on the podcast at https://lastweekin.ai/ In this episode: OpenAI released GPT-5.5 Instant as ChatGPT’s new default model, showing large benchmark gains and crossing a “high” cyber-risk threshold under its preparedness framework, while bio-safety results were mixed. OpenAI investigated and patched ChatGPT’s “goblin” obsession, attributing it to reinforcement-learning rewards that over-amplified playful creature metaphors in a nerdy persona that later bled across versions. Major industry moves included xAI’s Grok 4.3 price cuts and voice tools, Mistral’s unified Medium 3.5 model and Work mode, and Anthropic’s managed-agent upgrades alongside a surprise SpaceX compute deal and reports of a much higher Anthropic valuation. Key policy and security developments covered the Musk–OpenAI trial details, Pentagon AI deployments on classified networks, expanded U.S. government pre-release model reviews, and reports of NSA testing Anthropic’s Mythos on Microsoft software. Timestamps: (00:00:10) Intro / Banter (00:01:14) News Preview (00:01:39) Response to listener comments Tools & Apps (00:10:40) OpenAI releases GPT-5.5 Instant, a new default model for ChatGPT | TechCrunch (00:15:23) ChatGPT Became So Obsessed With Goblins That OpenAI Had to Intervene (00:24:14) xAI launches Grok 4.3 at an aggressively low price and a new, fast, powerful voice cloning suite | VentureBeat (00:30:49) Mistral's new flagship Medium 3.5 folds chat, reasoning, and code into one model (00:36:28) Anthropic updates Claude Managed Agents with three new features - 9to5Mac (00:40:42) ElevenLabs Revamps AI Music Platform as Fan-Focused Service Applications & Business (00:41:57) A diary, a threat, and a $30 billion stake: What the Musk vs OpenAI trial has actually shown in its first week - The Times of India (00:52:28) Anthropic, SpaceX Sign Deal to Boost AI Computing Power for Claude Software - Bloomberg (00:58:48) Anthropic in talks with investors to raise funds at $900 billion valuation, higher than OpenAI (00:59:37) Anthropic and OpenAI are both launching joint ventures for enterprise AI services | TechCrunch (01:03:15) Anthropic and FIS Are Building an AI Agent to Help Banks Police Financial Crimes (01:04:02) AMD’s revenue jumps 38 percent from last year as Q1 data center sales hit $5.8 billion. | The Verge (01:05:51) Banks seek to offload risk to avoid ‘choking’ on data centre debt (01:11:08) DeepSeek could be valued at up to $50 billion in first fundraising, sources say | Reuters Projects & Open Source (01:13:14) Natural Language Autoencoders Produce Unsupervised Explanations of LLM Activations (01:19:23) OpenAI just open-sourced its data center networking technology Policy & Safety (01:22:02) Pentagon inks deals with Nvidia, Microsoft, and AWS to deploy AI on classified networks | TechCrunch (01:24:27) Google, Microsoft, and xAI will allow the US government to review their new AI models | The Verge (01:29:11) NSA Testing Anthropic’s Mythos to Find Flaws in Microsoft Tech (01:32:42) Introspection Adapters: Training LLMs to Report Their Learned Behaviors Research & Advancements (01:38:18) Recursive Multi-Agent Systems (01:48:47) Frontier Coding Agents Can Now Implement an AlphaZero Self-Play Machine Learning Pipeline For Connect Four That Performs Comparably to an External Solver