Even though they can be fitted with pantographs, who would want them? Most rolling stock coming up for replacement is diesel, so the 701s can't replace them. The oldest EMUs still in use are the class 318s and 320s, and I can't see Scotrail having a use for 10-car units. Likewise Andy Burnham might like to replace the 323s on his "Bee" network, but again 10 cars is far too long for platforms in that area.
That leaves the Networkers on South Eastern, but is there any reason to think the 701s would work on 3rd Rail any better because they had crossed into the Eastern Hemisphere? And in any case SE has very expensively extended its stations to take 12-car trains.
And in the meantime, the 455s are just expected to soldier on until the new order is delivered?