Well done to Redis for making this clear
I once believed that the OSD did a good job of defining the criteria for open source licenses. That changed by experience of how it's actually applied, how it fails, and how OSI fails to redress.
The more I dug into available mailing list archives, the clearer it became that the problem isn't new. It's not just strong copyleft licenses and the constant stream of human rights licenses. It's the FRAND standards patent problem. It's the license-or-contract confusion.
The situation now, as I see it, is that OSD is largely window dressing for OSI. The OSD is vague and incomplete, but sounds official and technocratic. So it functions as window dressing for the prerogative of those with sway at OSI, to call it as they see it.
On that note, the title of the article is misleading. Redis hasn't changed its open source license. Redis remains BSD-licensed. This article is about the change in the proprietary license of certain Redis Modules.
It's more like an especially generous version of shared source than open source.
[1] https://opensource.org/osd [2] https://www.debian.org/social_contract#guidelines
https://referencesource.microsoft.com/
You can mince words and make inconsequential adjustments to proprietary software licenses but they are still proprietary.
.Net Core and .Net Framework are separate implementations of .Net Standard.