Statistically nobody is using valkey.
What evidence did you find?
This is Open Source working well.
Unfortunately, the reverse flow does not work.
Did they maintain the author's copyright notice as required by BSD-3?
https://trends.shodan.io/search?query=valkey_version+port%3A...
Here's a chart of all Redis-compatible services (~55,000):
https://trends.shodan.io/search?query=port%3A6379+redis_vers...
It was pretty easy, a small config change and some performance testing to make sure it worked well at scale.
Maybe nobody is talking about it online but some people have definitely switched.