It is no longer open source under the definition of Open Source Iniciative, FSF, Wikipedia, RedHat, Cambridge Dictionary, European Union, maybe even Redis themself… Only startups that want gratis marketing seems to disagree.
We had pretty much defined open source for the last 20+ years and one of the requirements is freedom of redistribution at least equal to the developer itself.
For what Redis is doing we already have term source available which makes perfect sense and both are well defined.
If you think open means just “you can see the code”, you must prove yourself at this point.