The authoring date is, yes. But not the "remind me at" date.
As for author: yes definitely. And it's a great fallback option. But it's not visible in most code review UIs, and even when it is it tends to be the most recent editor, not the author. Git's CLI makes the full history of a line pretty easy to read with -L (usually, depending on if it detects a move or not), but have you ever tried to do that on GitHub? Back through several versions? It's a freaking nightmare, and nobody will try to do that while reading a diff.
As for author: yes definitely. And it's a great fallback option. But it's not visible in most code review UIs, and even when it is it tends to be the most recent editor, not the author. Git's CLI makes the full history of a line pretty easy to read with -L (usually, depending on if it detects a move or not), but have you ever tried to do that on GitHub? Back through several versions? It's a freaking nightmare, and nobody will try to do that while reading a diff.