I guess you could call it alpha testing, but I’d just call it smart development. They have to make these things anyway, so add the pieces that work into the existing game so you can make more money while you work on the new game. You also get free press and good PR for giving existing owners more stuff. It only makes sense.

(There are some people who will cry “asset reuse” and complain probably, but in what world is doing more with less bad? Reusing stuff you made is smart and good so you can focus on new things.)