I highly doubt Northumbria will get much new stock in the next few years considering they've just paid for a significant chunk of them to be made Euro 6 and the only Euro 6 requirement South of the Tyne is the X12 which have already been converted.
The fleet isn't even that old!!! Why all of a sudden do we feel they all have to be replaced every few years because of a superiority complex towards certain routes?! the average life span of a decker is around 15 years IIRC so doubt much will be binned off beyond the 55 plate B7TLs at Belmont before the end of 2024 (minus Lowlanders as some have already been scrapped) and even then probs be a bit further down the line.
The North East fleets of most companies is still better than some for age, look at some of the old crocs First is running around in parts of the UK compared to us, hell look at some of the Arriva fleets, North East spotters bemoan us having 05/55/56 plate MPDs running around until recently yet some divisions still have some in active daily service hitting 20 year old!!!
Max Brand