https://redis.com/blog/redis-adopts-dual-source-available-licensing/
This is the announcement.
This is a disappointing outcome but one that I think has been coming for a while. Amazon has profited off of Redis without giving much back for quite a while (at least I recall this being a complaint of the Redis folks, perhaps others have evidence to the contrary).
This is pretty clearly an effort to bring AWS to the table for negotiations.