That would be great as being able to recompile MUI apps to run natively on Linux would open up a whole new world of opportunities.
This is just nonsense, for so many reasons.
MUI is bound by "the Amiga way", which is totally different from "the UNIX way" that Linux follows. I have never heard anything about using MUI on Linux, it's totally pointless anyways, there is no "AmigaOS" compatibility layer in Linux (and for a reason, noone needs it). What you think of is probably various efforts to create bridges between toolkits used on X11 and MUI, to make porting of X11 applications to Amiga systems easier by using MUI.