I could be wrong, but I can't see that being particularly likely:
- Freightliner's withdrawal of their class 86 locos suggests they have no requirement for electric traction beyond what can be provided by their existing class 90s, for similar economic reasons to DB.
- Direct Rail Services have ten modern class 88 locomotives with basic off-wire diesel capability for a comparatively small number of flows over primarily electrified routes.
- Rail Operations Group have thirty brand new dual-mode class 93 locos beginning to be delivered.
- GB Railfreight have thirty bi-mode class 99 locos on order.
I think that essentially just leaves Colas, who, barring one very brief foray with a class 86 ten years ago, haven't taken up electric traction as I suspect it wouldn't be appropriate for the flows they operate.