At the very least you have to validate everything that touches redis, which means finding everything that touches redis. Internal tools and docs need to be updated.
And who knows if someone adopted post-fork features?
If this is a production system that supports the core business, hundreds of hours seems pretty reasonable. For a small operation that can afford to YOLO it, sure, it should be pretty easy.
The negative effect is that you have to bring the lawyers back in, and they tend to take an extremely conservative position on what might be litigated as offering “Redis-as-a-service”.
Many legal departments cannot afford nuance when a newsworthy license change occurs. The kneejerk reaction is to switch away to mitigate any business risk.
And who knows if someone adopted post-fork features?
If this is a production system that supports the core business, hundreds of hours seems pretty reasonable. For a small operation that can afford to YOLO it, sure, it should be pretty easy.