It's OSS, so how is it possible for the project to end development? The lead developer, yes, but as long as there's source, the software is never truly EOL. (obviously the "canonical" distribution channel is where the question truly lies)
More often then not, someone doesn't pick up from the developer and it just... fades away. Shame, Latte is a fantastic project and is incredibly customizable and uses less resources off KDE's bars.