I pushed the AdaCore announce on Hackernews, it seems to be available : Ada Crate of the Year, 2024 | Hacker News
You might try on Reddit?
There’s of course the r/ada forum. Much wider (4+M subscribers!) could be for example the r/programming forum.
I’m less ambitious : I joined the software testing group last week, only 38K subscribers. 
But didn’t post yet.