If they choose to discontinue it, it would be nice to have them opensource it so that the community could have a go at maintaining it tbh. Surely that's better than letting it rot (both rosetta and the old software that it runs).
That would be ideal, but given Apple's general hostility towards Open Source, it sounds extremely unlikely. I wonder what it would take to re-implement it. If it's "just software," I suppose there is a chance, not that I'm volunteering :)
Apple really isn't as hostile towards OSS as people think. With that being said, the reason to discontinue Rosetta 2 is to push developers to upgrade their software. Allowing others to continue using Rosetta 2 by way of 3rd party maintainers works against that goal :(