Is it just me who thinks they are taking the complete wrong approach for this and all the buses are going to be absolutely chaos as a result?

Personally imo it would be better to do something like

X66: Blaydon - Metrocentre - Metro Centre [Express]
X100: Metrocentre - Newcastle [All Stop]
X200: Newcastle to Gateshead Interchange [Express] 

10/10A/10B: Newcastle via Scotswood Road, change to X66 for Metrocentre
X45/47: Redirected to Blaydon and into Newcastle via Scotswood Road, change to X100 for Metrocentre
6: Terminate short at Metrocentre, change to X65 for Newcastle

All Gateshead services: Terminate at Gateshead, change to X200 or Metro for Newcastle

Least the other 95% of the bus routes would actually be running on time.

It's going to be absolute chaos imo.