Yes, I too would’ve thought they’d be next from Lothian once the 15 plate B5LH’s are complete. I think that will still happen as there’s just 3 B5LH’s left now - 562, 565 and 569. 568 is back at Longstone and may even return to service this afternoon, but probably tomorrow. 497 has also returned to Longstone, but it might be a bit longer before it’s back out.
579-590 on the other hand (I think as we’ve all worked out by now) are more than likely moving to another division, hence these being repainted prematurely, after just 3 years (584 after 5 years).