Exceedingly, exceedingly unlikely because AMTK already has the contract signed/sealed for the 150 national options on the Charger. That's the cover-your-butt boilerplate legalese if the corridor base order were some sort of epic disaster and they needed to rebid. There's a 0.0% real-world chance they're going to do anything but tap the Siemens options they already have contractual access to. The RFI just repeats for document compliance purposes what's already been settled for years about what Siemens is going to deliver for those 150 national options on the contract.
The corridor vs. national specs difference probably does include some tradeoffs for speed vs. HEP load given that these are the LD-certified versions that have to haul power-hungrier diners, sleepers, lounges, etc. that the plain old coach-hauling corridor/commuter Charger doesn't. Bigger fuel tank capacity is the main physical difference, but the slight differentiation between nat'l vs. corridor units also entails different performance optimizations. Corridor units will never be in rotation on an LD set outside of one-off tag-alongs for equipment swaps, while national units will be jack-of-all-trades like the P42's and must be calibrated that way. That includes being jack-of-all-trades on all the Eastern state-sponsored routes where electric-to-diesel engine change points by necessity force those state routes to draw from the same diesel pool as the LD's and Regionals that engine-swap in WSH, ALB, NHV, etc. Or where the handful of isolated diesel-only route outliers (Springfield Shuttle, Downeaster, Heartland Flyer, etc.) have their locos laundered out of a nat'l engine-swap or LD equipment base making a buy of self-owned corridor Chargers logistically impractical for those states.
The only places where 125 MAS on diesel is ever going to be fully realized are on the routes where the states have already bought the 125 MPH-rated corridor configuration: the emerging HSR corridors in the Midwest, and Cali when routes like the San Joaquin start relocating partially over to CAHSR. Diverging NEC routes will always swap from electric at WSH, NHV, or Philly/Harrisburg so 125 on the diesel legs isn't a consideration for the 25-year + rebuild lifespan of this nat'l order. The Empire Corridor will hash these 110 vs. 125 MPH MAS considerations out with its separate dual-modes order still to come. And Springfield and Richmond will be electrified when they finally demand speeds >110 because electric acceleration is the far bigger difference maker than raw MAS when it comes to those NE Regional routes' denser stop spacing. I can't think of any route chained to the national pool where this pretty minor speed difference is going to pose any sort of constriction over the maximum foreseeable lifetime of the vehicles. At the rate we're funding things not even the corridor order is ever going to see a real-world 125 odometer reading in revenue service. But nonetheless all the places that are "couldas" and "shouldas" for emerging-speed HSR are the ones who've already plunked down for the 125 MPH units, so they have it covered if their designated corridors ever do get some $$$ love. Once NEC electric & ALB dual-mode engine swaps are factored in, the rest of the country tied to the nat'l diesel pool simply doesn't overlap enough of those futuristic >110 corridors for it to be any consideration. In the highly unlikely event that changes...pull aside a few dozen of the large-tank units for re-tuning mods to 125. It's a slight enough performance difference that it should be a wholly orthodox change doable without major rebuild.