Ah cool, I didn't know that! I'll update the blog post. (What a cacophony of flags)
Edit: It seems that grep -0 isn't taken for something else and they should have used it for consistency? The man page says it's meant to be used with find -print0, xargs -0, perl -0, and sort -z (another inconsistency)
It is taken in grep, just poorly documented; grep -5 means grep -C 5, and grep -0 means grep -C 0. It's not taken in sort, though, so I don't know why they didn't use -0 for sort.
Takeaways: (1) There is no consistency in flag names, even --long ones (2) impressively many tools do support it! Note that some affect only input or only output. (3) All do NUL-terminated, not NUL-separated. That's fortunate — matches \n usage, and gives distinct representations for [] vs [""].
It's best to give up on any kind of consistency between command options. Any project is free to do anything it wants, and they all do. Someone is eventually going to come up with standard N+1[1] which does things consistently, but they are going to have to either recreate a bazillion tools or create some sort of huge translation framework configuration on top of existing tools to get there. And even then it'll take literally decades before people migrate away from the current tools. Basically, the sad truth is this isn't going to happen.
Edit: It seems that grep -0 isn't taken for something else and they should have used it for consistency? The man page says it's meant to be used with find -print0, xargs -0, perl -0, and sort -z (another inconsistency)