I'm not sure if the construction work affects Rabbit Banks Road, I've seen council gritters and buses running up there despite the "closure".
I don't think there is a need for a busway for a service running in one direction only every 10 minutes from a shopping centre in decline. GNE have already demonstrated that they can do without the Centrelink, too. If the council redid the Bottle Bank slip road to allow traffic to make a wide turn and merge onto the Tyne Bridge, then the Centrelink would be useful and it wouldn't clog up the Quays, Sage or Swing Bridge. Not funnelling all traffic through Gateshead would ease congestion and is less likely to disrupt buses.
RE: Gateshead Sunderland Road Bus Link