Could someone more knowledgeable explain what the practical effect of this license change is? As far as I can see, there isn't much of a difference?
The practical reasons are almost entirely about legal minutia. It opens up some possibilities, like being able to seamlessly use OTHER CC-BY-SA 4.0 content, but there won't be any concrete tangible difference to readers. A while back stackoverflow went to CC-BY-SA 4.0, and bunch of people got into a snit about it: https://meta.stackexchange.com/questions/333089/stack-exchan... No one could ever explain what the actua…
Wikimedia got it right by putting "3.0 or later" in their terms of use (TOU). This allowed them to _legally_ claim all old contributions are available under 4.0. They're still also available under 3.0, but that's a minor detail.