There'll be some way to make it work, possibly indeed that the Homebrew people get approved by Apple, because MacPorts works ok, and it seems to be downloading precompiled binaries (and if it isn't, then my Mac is actually faster than I've ever seen it run). And if MacPorts can do it, presumably Homebrew can do it too.

Building stuff yourself remains an option, even if you're unapproved. The toolchain pops the codesign step in at some point, I guess, and if you built it locally then you can run it locally. I just did cc -o on some bit of code on an Apple Silicon Mac, and the resulting binary did run.

(You can also run binaries that unapproved people built on other systems, but it's a minor pain, as you have to explicitly opt in to allowing each runnable file to run.)