Its not unexpected to move Wrightbus Ultraliner's to Wigan, as Wigan will possibily be the last depot to have anything electric, simply because its difficult to electrify at the rear of a large industrial estate, and would cost a lot of money to do, therefore it makes sense to send Streetdecks to Wigan to make the double-deck fleet entirely Streetdeck. However what I am not sure about is why, MX58 Volvo B9's would be re-instated, surely something could be moved out of Bolton in exchange, perhaps the B9's there, would be a better bet, seeing as they are being replaced at Bolton/Heywood with the next batch of electric's. I presume that the changes at Wigan will not be as simple as putting the ex Metroline Streetdecks on the 609, and more likely they would be allocated to 610 board's, as that is Wigan's busiest route and has always been favoured newer vehicles than other routes at Wigan Depot in the past.