I kind of like the idea that it’s vague, since it allows the viewer to imagine as many Jedi as they want. Luke did have a school, so he could have rescued some of his students. Of course he didn’t, but I’d like to leave that possibility open as long as possible, to heighten the mystery around the Jedi at this time.

Here’s another attempt, trying to make the sentences less clunky:

THE FORCE AWAKENS

The galaxy is in peril.
After many years of peace,
the last of the Jedi Knights
has vanished.

In his absence, generations
of fanatic soldiers, stationed
on a secret Imperial base,
have completed a weapon
that can devour entire stars.
Without the protection of
the Jedi, the New Republic
is blind to this hidden
threat.

Only one leader resists
this evil FIRST ORDER.
Mobilizing her most loyal
officers, she sends her
finest pilot in search
of the long-lost Jedi,
master of the vast
and powerful Force…

Needless to say, here I’m playing up the legend for all it’s worth. 😉