[bananapub]

truly a bizarre way of doing a dumb thing - they do not own the copyright of all the Redis code, so they cannot "change the license" of the existing code at all.

instead, they need to license their new contributions under the new license, which will effectively make the combined blob of code only available under the new license.

doesn't change what they're doing, but it's just disrespectful, incorrect and a breach of everyone else's copyright to remove the existing license and headers.