Migrating a bunch of old and new dbs from Redis 6.x to Valkey 7 went smoothly here.
If you're migrating: 7.2 is the ideal version to switch over. If you upgrade Redis above it, compatibility guarantees drop.
For his return to redis: https://antirez.com/news/144
On his new vector sets feature: https://antirez.com/news/149
https://archlinux.org/news/valkey-to-replace-redis-in-the-ex...
https://redis.io/blog/redis-adopts-dual-source-available-lic...
https://archlinux.org/news/valkey-to-replace-redis-in-the-ex...