Yes. It was announced in late November by Scotrail, as part of the Airdrie-Bathgate opening cascades.
Link
The 380s are coming to run all Inverclyde and Ayrshire services, meaning that all 334s, 318s and 320s will be running on services through Partick. North Berwick's also getting the new trains, to allow the 322s to go back down South.
What are the plans for the new units? Class 334s will be diagrammed to exclusively operate services via Airdrie and Bathgate (Milngavie and Helensburgh-Edinburgh) with 318s operating on the Argyle route. The 320s are to supplement the North Clyde diagrams, but will not be running beyond Airdrie, and 8 units will be diagrammed onto the Argyle Line.
This raises some questions:
- How will the Argyle Line be equipped for Class 320 operation? DOO equipment, including mirrors and cameras, needs to be fitted at various stages across the line. An alternative would be to simply attach 320s to the back of Hamilton Circle service, although this would be restrictive and totally moronic.
- Will the 75mph 320s be able to operate to Lanark and through Cambuslang at the current timings? These sections of line are faster than the 320s' maximum speed.
With 8 units out of the 22 set to go to Argyle, that leaves 14 for North Clyde services; quite a lot considering that "only" 4 would be needed for a Dalmuir-Springburn service. You'd have another 10 floating around. This is more than enough to operate a Balloch-Airdrie service on top of the Airdrie-Bathgate services (ie, doing what currently happens in the evening peaks, but throughout the day). The stock is available for this, but it's purely speculation on my part otherwise. They could simply choose to run Balloch services to High Street, for example (although I do think maintaining this terminating at High Street charade would be rather foolish).
Whatever happens, you will get 8x320s about this time next year. You have my deepest condolences.