I feel copyleft licenses look more favourable at this point of time. What’s the value of more free/business friendly licenses if you can’t guarantee that the same license will apply for all the future releases? Looks more like a bait and switch policy.
Am I right in understanding that the relicensing was possible because of the CLA, not just because of the BSD license? Would a permissively licensed project that didn't use a CLA be vulnerable in the same way?
A key concern is that BSD isn't viral, so anyone can take BSD Redis and fork it into a commercial offering. If you want to, you can. The Redis trademark prevents anyone but Redis the company from calling their fork "Redis".
A CLA may impact relicencing, it depends on the terms. A simple CLA may only say "I am the owner of the code and I release it under $LICENSE". The current Redis CLA also has a copyright grant, which gives Redis the company greater rights.
“Viral” just means that the license has a “no additional restrictions” clause, not that you can’t make a commercial offering out of it. That’s why GPL and AGPL don’t really solve the problem.
And the problem with the trademark model is that AWS, and especially Microsoft, already have established brand recognition with the people who sign the big SaaS and support contracts. The people who know what a Redis is are just nerds with no money, the real big shots do everything in Microsoft Excel.
A permissively licensed project without a CLA would be similarly vulnerable, because the BSD license allows them to make releases that include your code under a stricter license. To prevent them relicensing you would need both a strong copyleft in the license and no CLA/copyright assignment (like e.g. Linux - which can't even move to GPLv3 even if they wanted to, because it would be simply impossible to get all contributors' permission).
No, since you can include BSD-licensed code in non-free software with just an attribution. The only difference between relicensing Redis from BSD+CLA to SSPL and BSD to SSPL is that the former would've had a more detailed REDISCONTRIBUTIONS.txt.
The copyright owners of a GPL software can do whatever they want with future versions, even going proprietary. The problem is that all the owners must agree on that. That's why some GPL software only accepts contributions by people that give copyright to a single maintainer entity. An example is FSF's copyright transfer, which to be fair is more nuanced than that and has also other purposes.
