Revision 8 of the question addresses these concerns.
Answers are not the only part of the content that can be used as knowledgebase and where posting AI content can do harm we are poorly equipped to deal with, besides relying on AI policy. On Stack Overflow there are also articles and discussions.
Instead of using word answers, use word posts in AI policy text. Or at least explicitly name articles and discussions there, too.
When warning users about posting content other than answers linking to AI policy that explicitly mentions answers leaves plenty of room for interpretation. It may look like the answers are the only parts where AI is not allowed.
Similar request has already been made at Stack Overflow Meta Extend AI content policy to articles and other content that is meant to be used as part of the knowledgebase
