AWS is committed to supporting open source Valkey for the long term. We are adding Valkey support to our ElastiCache and MemoryDB managed database services and contributing to the open source Valkey project.
I think it's not exactly money, but avoiding a scenario where their business can be held hostage by a company which in practice is trying to force them into a commercial license.
Notice that AWS is far from being alone in this move, as the massive support around Valley shows.