I read the post and it’s not clear why it’s not MIT licensed. Why not allow attempts to “create proprietary distributions?” That’s what open source would allow, no? I honestly do not see this as being different than Redis. Do BSD or MIT and be done with it. It seems needlessly ideological. Everyone wants to call their stuff open source but have strings attached.
The term 'Open Source' is well-defined and includes licenses like the one redict picked (LGPL 3.0). It is incorrect to try and lump this in with source-available licenses that are IMO anathema to Open Source.