AFAIK the task is looking for volunteers (who have the necessary low-level knowledge) and/or funding. The mailing list at openmcl-devel@clozure.com has some threads related to it - see https://lists.clozure.com/pipermail/openmcl-devel/
As a Lisp neophyte, I've been watching the Clozure CL situation with some interest -- I really want to give it a try, especially the macOS/Cocoa bindings, but my only Mac at the moment is an M1. A couple of specific questions I've been wondering about:
1) Does the port require a rewrite of the compiler? It seems like it was only ever released for 32-bit ARM, not even generic ARM64? How much of that work can carry over to an Apple Silicon port?
2) Will the announced rewrite of Core Foundation in Swift and/or the transition to SwiftUI put the CCL Cocoa bindings at risk of obsolescence anyway?
My current job doesn't demand much coding out of me, so I feel lucky that I'm able to focus my personal learning efforts on interactive development environments like Lisp and Smalltalk, and grateful that solid free implementations are available in any event. If somebody does start up Apple Silicon CCL crowd-funding, I'd be in for at least $100.