The new interim policy concerns what the Community Management team will accept for reports and appeals. For details, see (Interim) Policy on AI-content detection reports.
Moderators were never restrained from deleting posts that blatantly are very low quality (VLQ), other than voluntarily restrained by themselves as part of the moderation strike. When a moderator found a VLQ, regarding the deletion of the post, it doesn't matter if they were written with or without the help of generative AI tools. Due to the new policy, what might be changed are the heuristics used to determine if a post content will be treated as being created by generative AI tools to apply / request additional penalties to the post creator.
Without seeing the specific cases, we can't infer the deletion cause of each of them; we can only deduce what might have happened based on the personal experience of each of us and the literature reviewed.
I'm a member of Stack Overflow with the privilege to vote to delete, and a community moderator on Web Applications SE. In both communities, I have seen VLQ posts where GPT detectors reported a very high probability of being GPT generated that are grammatically correct but show AI hallucinations, as they include Google Apps Script / JavaScript methods, among others, that don't exist and point to documentation that doesn't exist either, the included hyperlinks return error 404, page not found. On Web Applications SE, as moderator, I will delete these posts. On Stack Overflow, if the post already has enough downvotes, I will vote to delete it.