The pendulum swings fast in agent engineering: the same lab that championed orchestrator-worker patterns now tells teams to collapse their subagent fleets into one model with on-demand context. The underlying logic is solid — every subagent hop multiplies token spend, latency and coordination failures, so as models get better at holding complexity, orchestration layers turn into dead weight. But a 2x speedup in one comparison is not a universal law: fan-out still wins on genuinely parallel workloads, and Anthropic's own earlier multi-agent research results showed big gains there. The meta-signal is the real story — agent architecture fashions now cycle fast enough that a lab ships a migration kit for a pattern it promoted not long ago. If your stack is built on orchestrator-worker designs, treat this as a prompt to re-audit costs, not as a verdict.