All you basically need to know is:
MechScape is a code name; the real name of the game is Stellar Dawn.
Secondly, Jagex keeping pushing empty promises so don't get too excited about anything. When asked, "When will the game be released?", they reply, "Soon" but it's been many, many months. Another example of this is how they canceled the MechScape Official Question and Answer session.
And the last thing you need to know is the head dude that was working on Stellar Dawn, Henrique, is no longer employed at Jagex, so the game's released date might be pushed back even further.