Update posts/2025-01-09-Rust-1.84.0.md

Co-authored-by: Josh Triplett <josh@joshtriplett.org>

Author: Mark-Simulacrum

posts/2025-01-09-Rust-1.84.0.md

@@ -28,14 +28,7 @@ aware selection allows library authors to easily adopt newer Rust versions
 while allowing consumers of the library to automatically use old versions
 if they need compatibility with older toolchains.
 
-Library authors should start declaring their MSRV. Previously, bumping the
-version at each release to latest stable would force downstream consumers
-requiring an older Rust version to avoid running `cargo update` and/or require
-pinning the version of the library in use, but now those consumers will be able
-to automatically avoid pulling in new library versions if they want
-compatibility with an older toolchain. We expect this to provide more options
-for library authors for picking their preferred support strategy for Rust
-versions.
+Library authors should take the MSRV-aware resolver into account when deciding their policy on adopting new Rust toolchain features. Previously, a library adopting features from a new Rust toolchain would force downstream users of that library who have an older Rust version to either upgrade their toolchain or manually select an old version of the library compatible with their toolchain (and avoid running `cargo update`). Now, those users will be able to automatically use older library versions compatible with their older toolchain. In the future, we expect this to provide more flexibility for library authors to select their preferred support strategy for Rust versions, without worrying about users on older toolchains.
 
 The new resolver will be enabled by default with the 2024 edition (expected to
 stabilize in 1.85), but can be enabled as of 1.84 by setting