Mozilla replaced Reading List (which was client-side encrypted and theoretically self-hostable) with Pocket (which is neither). Search engines need search terms to function; Pocket uses user data to support a particular business model.
Reading List was still in development when it was canceled. Anyone who preferred Pocket was free to install it.
Continuing the current revenue model and supporting Context Graph seem at odds with improving user privacy. Pocket isn't now Free Software, but hopefully it will be feasible to self-host whenever they do release the source.
