Currently there's a big controversy over SE changing the licensing from CC 3.0 to CC 4.0. Regardless of whether this change was legally solid or not, could someone provide a specific example of how this licensing ambiguity affects our ability to copy, share and reuse content published on SE in the past?
Let's say I find an interesting piece of code on StackOverflow from 2017 and add it to my open source project with attribution, citing CC BY SA. Could the author of this piece of code claim a copyright violation somehow, given the licensing ambiguity? The way I see it - the code is licensed under either 3.0 or 4.0 and the difference between the licenses is so small in practice that knowing the exact version shouldn't matter. Whoever wrote the code couldn't suddenly claim that the licensing change completely revoked their original CC attribution, making it impossible for others to reuse their content.
Note that I'm not interested in whether or not the licensing change was legal/moral/appropriate/cool. I'm merely asking about how it affects my rights to reuse content posted on SE.
I believe users on this site are more qualified to help us in this matter. Could you provide a definitive answer to the question above?