I'm unsure how reliable the Bus Times website is, however:

The following vehicles seem to have been VOR for over two weeks?

12068

22346

27506

27508

28010

28031

The following vehicles appear to have been VOR for a long time as there are no "last seen" dates, are these being repaired?

39711

36479

22508 & 22069 appear to have returned to service at Slatyford - unless the ticket machines have been swapped and have not been reconfigured?

Are ADL E300s 27506-10 staying at Stockton once all of the E200MMCs enter service, as two appear to be VOR as per above?