Hi, co-creator of Valkey here. I'm not that worried about it. There are a lot of people who have tried to maintain Redis folks, my employer AWS has one such fork I know very well, and they quickly become extremely hard to maintain with your own code. These aren't problems Redis wants to solve, they are off in their GenAI space building fancy extensions. For the next year or so it might be a real concern, but we are thinking long term, and I don't think it'll matter for long.
So, we thought the best approach was to stick with the license and get us into a vendor neutral foundation. We haven't ruled out LGPL, we just didn't make the change unilaterally and as a foundational part of the fork. We just want to keep building :)