Hello all and thanks for contributing to this discussion.
It is correct that some composer warnings, such as the revive-old-topic or “necro posting” have been removed.
We wanted to look at improving the experience of these warnings in general; the original type was often perceived as annoying, since it filled the entire preview panel and blocked the writing process.
To address this, some warnings have been paired down, so they take up less space.
For others, we decided to remove them.
For the one specifically discussed here, our reasoning was that the goal of preventing necro-posting didn’t align with our values: we believe that content has longterm value, so why would we discourage participation in a topic that someone wants to discuss? We would rather have a topic revival than encouraging people to create duplicate topics, which would be the implied alternative.
Because of this, there are no plans to bring this back, and your best bet would be to make a TC for it.
Hope that clears it up!