Merged means that the changes are in main. Usually, forums don’t track the main branch; instead, they track latest. This means that after merging, you still have to wait for the automatic tests to run and pass.
When you are looking at Commits · discourse/discourse · GitHub, you can see that this has just happened with zogstrip’s commits (there is a green check mark, while the commit above still has the brown dot).
And you can now also see the commits when looking at the latest branch: Commits · discourse/discourse · GitHub
So if you are tracking latest, which forums do by default, you can update now to pull those commits.