This should be merged the next time we publish a release that a significant number of nodes will likely upgrade to.
If you run it before then, you may end up having to decompress/recompress blocks you send over the p2p network when talking with nodes running old versions. It's a minor thing, and you probably won't notice any performance penalty for doing so.
There's nothing unsafe about this MR, and it's fine to run it. It's just marked as a draft to prevent it from being merged until the next public release.