Why use a GPL license ? This kind of port could have been the occasion to get rid of this type of license.
Why port Emacs to Rust ?, it adds no value to users. Why not develop a modern GUI like Intellij IDEA with a Common Lisp implementation underneath like SBCL ?
> "Whereas IBM's PC (and almost all PC compatibles) had a power supply in a corner of the main case, the PC1512's power supply was integrated with that of its monitor. The monitor had sufficient venting to cool itself by convection, instead of needing a fan. The PC1512 was therefore quieter than other PCs. Rumours circulated that an Amstrad PC would overheat, and while existing owners would note that this did not happen, new buyers were discouraged. As a result, later models had a cooling fan integrated into the main case."
I was in the same mood. Now I 've stopped coding for a living (you can try management, presales,...) and at home I do what I like (exploring data structures and algorithms) with the tools (Emacs) and languages I like (Common Lisp)
If you are a 100% manager, then you will not be able to pair program for a long time as your programming/technologies competences will fade away quite rapidely.
When Guido Van Rossum will tell Python 2.7 is now PyPy or when he will say "we don't support python2 anymore", then pypy will become the python2 de facto standard.