fwiw, when we did the plugin splits to and from ansible-plugins-core/extras, we found that the majority of the issues/prs we moved became unmonitored by the original author. Not by any actual technical mechanism, but many were drive by contributions, and we ultimately just closed a vast majority of them.
The core team isn’t likely to run any script like the bot to move them, and not likely to grant permissions for another bot maintained by someone outside of core to close issues and PRs.
Our operating mechanism would be to just close them, and tell people where the new repo is. As it is, we move very few, and I’m probably the only one who has done it due to permission requirements.