Update: I have started a GoFundMe in an attempt to have a court or arbitrator settle this.
On 2019-09-05, Stack Exchange announced that all subscriber content would be available under the CC BY-SA 4.0 license. 34 hours after this announcement, I asked in a comment if that change had been run by the legal department. In the following days, I had not received a response, so I posted a follow up comment, which was promptly removed. I did this again, and ultimately got suspended for a week for repeatedly asking a time sensitive legal question. The original comment currently has 81 upvotes, the most of any in the chain.
I contacted Stack Exchange via their contact form a week ago, and did not receive a response. It is now 17 days after the announcement, with the window (in 4.0) to correct license violations being 30 days. As such, I am asking this again in a standalone post.
Pursuant to the 3.0 license section 4(a)
You may Distribute or Publicly Perform the Work only under the terms of this License.
This single clause makes extraordinarily clear that the original work (which the content is) cannot be sublicensed. Some people have made the argument that it's not clear what the original license was, as a version was never explicitly mentioned in Stack Exchange's TOS. I don't believe this would carry weight, as the announcement makes clear that the content was originally under the CC BY-SA 3.0 license.
My non-legal opinion is that this change is not allowed under the terms of the original CC BY-SA 3.0 license.
Has the retroactive license change been run by Stack Exchange's legal department?
Yes or no. If yes, what clause allows you to do so? That's all I'm asking. Don't give me and the community sly and disrespectful comments about how we're not lawyers so we can't have opinions, which has happened in chat. I will personally interpret the lack of a response as a "no".
Per the 2018 ToS update, Stack Exchange made clear that
We don't want things to come to litigation, ever.
We don't want things to ever come to actually having a case in litigation, nobody likes it.
We owe it to you, the people that have put hundreds — more often thousands — of hours of work into our sites, to maintain a conservative legal profile that is exactly sufficient to avoid litigious engagement in today's legal climate. ... we also can’t allow ourselves to fall short of a sensible or reasonable level of protection.
If this is still true, why has there been no response from Stack Exchange on this matter? Not responding may as well be asking for litigation, as there is no other means to resolve this situation.
Please join me in contacting Stack Exchange requesting that they answer this question. It is highly upvoted and has received no response from staff. I have flagged this question for featuring, which was declined.