tl;dr
Read the first sentence after each citation ;D

So Wayland, a protocol, is needing the addition of other protocols?

Yes. What we know as Wayland is the Wayland core protocol and a few other protocols that are absolutely necessary for desktop use (stable).

Then there is staging, which is not necessarily implemented by all compositors, e.g. fractional scaling.

Unstable also exists, which is even easier to get a protocol into (idk the exact requirements, likely the amount of support and explicit dislike by contributors).
These are often only used by a subset of compositors with e.g. XDG decoration allowing compositors to announce to clients (windows) that they support server side decorations (top bar with close/minimize/maximize buttons). This isn’t implemented by Gnome, but most other desktops support it.

Different desktops also have their own protocols, which are published so that apps targeting those desktops can implement them. Some are also supported by other desktops, if they think they are suitable for them.
E.g. wlr layer shell makes status bars possible, which are used by basic compositors like Sway or Wayfire. KDE also supports it, even though it was originally created by wlroots.

Does this make it a Wayland Distro?

In a way you could say that a compositor is a Wayland distro, as it implements a subset of Wayland protocols.

In the end this is good, because it allows for rapid development and discontinuation of protocols. E.g. if a better protocol comes around, both protocols can be supported at the discretion of every compositor.

The goal was to solve the problem of X11, where Xorg still has to support drawing UI by itself, even though no program or toolkit uses it anymore (the 80s were very different). The Wayland core is so minimal there shouldn’t be any issue with using it for a very long time.

Also, Wayland was developed by people with the goal to use it in automotive and other industry applications, where basic desktop functionalities, like multiple windows or session lock, aren’t useful.