This is an example of something that is neat on the surface but completely blows up in practice, after even a few moments of consideration.

First, what do you ask for in a query? Will some web sites choose to say “mozilla” and others “moz://a”, thereby splitting search traffic between the references?

Just typing something like “moz://a” (even in a comment post such as this) might cause some sites or scrub-analyzers to assume that the text represents a valid URL of type "moz" and try to make it clickable and resolve to that URL type. Bonus points for the first malware to figure out how to hijack the "moz" URL type.

What is their web site? Not "moz://a" but "https://www.mozilla.org". Can anyone even type "moz://a" or "https://moz://a"? Can’t wait for this to cause problems.