Maybe this comes close… https://simple-press.com/downloads/featured-topics-and-posts/

Will give that a shot

I have never tried it myself to be honest…

still sounds like you want some version of the template tags and widget plugin… which gives you multiple ways to display the latest stuff…  and if you are using the sneak peek functionality, they will see the forum and topic, but wont be able to view the post…  optionally, they can be blocked or directed to a page to sign up or other…