Wonder if the homebrew version of cp has it, too… afk now.

Depends on what you mean by homebrew version of cp. cp isn’t a package on homebrew, but I suspect you’re talking about the gnu coreutils which contain the gnu cp.

That one does not have the flag.

However I think you were still using the old macOS cp without knowing because long time ago when I played with this package, they all were prepended with a g. Like gcp instead of cp.

Yeah, I meant the cp provided by Homebrew, which is, as you point out, in coreutils.

I'm use GNU versions over local versions, in all cases. I have a script which links them into /usr/local/bin/.

I guess I can use /bin/cp if I need this.