Not seen that, but Grange Hill has a lot more flexibility to reinvent itself than DA, characters naturally got replaced because it was set in a school so there isn't the need for an actor to play an iconic character who people already know and love, have fixed ideas about and don't want to see "a reinterpretation".
It was cancelled in 2008, it would have changed several times over the course of it's run.
Depends if the director wants to make something with fresh ideas or "pay homeage" and gets weighed down trying to live up to by expectations of old fans.
Anyone watched watched the new ghostbuster film? The new characters were relatively interesting but the it was a terribly slow (and around halfway in, boring) film, meandering to get the point where the flaky old timers come back.