Probably this: https://news.ycombinator.com/item?id=43587420
If it ain't GPL and it IS popular, I think those kinds of things are more likely to happen than not.
Even GPL can't force a company to maintain and keep developing an open version when the company doesn't want to. Even if Redis was GPL (no CLA), they could still abandon it and write a compatible clone from scratch. AI makes it even easier to do