I'd predict 3 Omnis transferring to Washington as the spares for the 4 & 50 (and 5 whatever is happening with that) allowing 5324 and 5337/8 to transfer elsewhere.
I'll also predict a few also transferring to Stanley. Not only one to replace 5248, but also a few more to convert some of the double deck Toon Link boards to single deck with the Omnidekkas transferring elsewhere to replace B7TLs.
I don't know about the rest though. Perhaps the 19 could be a good option.
RE: Go North East: Upcoming Service Changes v2