Zuckerberg's reversal is not an isolated product decision — it is a signal that frontier capability and open weights are now treated as incompatible at Meta's scale. Muse Spark was built by the Superintelligence team, and its closure is the institutional answer to the question of whether that team would operate like the Llama team Meta's closed model strategy confirmed by The Register's April 8 coverage. It did not. The developers who built workflows, fine-tuning pipelines, and commercial products on the assumption that Meta's frontier output would remain open now…