That wasn't my take. I thought we were discussing the deprecation itself. It's true that nothing is broken yet[1]. But it's clear that "broken" is where we're going, and I don't think you or the GNU maintainers have thought through the implications correctly.
[1] At least, nothing that isn't sensitive to junk on stderr -- bourne scripts are not always as tolerant as you'd like.
We were explicitly discussing GNU grep 3.8, which does not remove anything, only add warnings. And the remote possibility of breakage due to warnings is why I qualified my assertion with “in all likelihood”.
[1] At least, nothing that isn't sensitive to junk on stderr -- bourne scripts are not always as tolerant as you'd like.