First, and most obviously, stack exchange does NOT own the forum content. It has been provided for FREE by the larger developer community, and that same community regularly makes use of the AI tools which will be inhibited by this policy change. Second, stack exchange is questioning the integrity of archive.org by hiding the data.
Developers are the real victims here, and the audacity of Stack Exchange to demand money for work they DIDN’T do, but continuing to NOT pay their forum contributors is peak irony.