I would imagine a better answer is for someone else in the community with familiarity on the project to create a semi-official fork. Perhaps a less destructive

I would imagine a better answer is for someone else in the community with familiarity on the project to create a semi-official fork. Perhaps a less destructive change that someone with access (Github, NPM, Microsoft, etc.) could make, is to link to the new project from the readme. Eventually when something breaks, this could be surfaced as an `npm audit` response (Core-js is no longer maintained. Switch to core-js-fork to resolve issue xyz).