AWS did not acquire the DuckDB technology itself, which is MIT-licensed open source and governed by the DuckDB Foundation which holds most of the related IP [1].
What they did acquire is DuckLabs, the Amsterdam-based services and development company behind the technology which is owned by and employs the creators and major contributors.
And MotherDuck is a US-based venture-funded commercial company, whose cloud-based data platform is centered around DuckDB but has been significantly expanded recently, including Python pipelines, an agentic context layer, and a visualisation layer.