I recall that was one of the ostensive reasons that TPE went for locos, 'so they could be made electric by swapping out the loco'.
In any case, I've not seen any railway or governmental authority actually express even intent to electrify those lines. So even if a proposals and funding assurance was given tomorrow, it'd be best part of a decade before entry into service. It seems likely to me that they would go for a discontinuous system due to the complexity of sharing with the DC 4th rail, and that would require a rolling stock order of battery/AC bimodes.