Yes, but the word rewrite implies that it would serve the same function and retain compatibility.
If someone wrote a new implementation of the x protocol, as a drop in replacement for the existing x.org server, you might call that a rewrite.
Wayland is an entirely different solution to the same problem. It doesn’t follow the x protocol, and doesn’t maintain compatibility with the x.org server.
Yes.
The only added flavor in standard chocolate chip cookie dough is vanilla. Plus the chocolate chips.
Of course people don’t usually think about it like that because vanilla is in nearly all baked sweets.