When discs started to take off properly in MTB, pretty much every manufacturer made bikes/frames that were "disc ready", some going further and speccing bikes with disc hubs, but Vs handling the stoppiness.
This seemed at the time to be a very good idea. Future proofing, and allowing the buyer to gradually upgrade. Maybe an end at a time, for example.
Why doesn't this seem to be happening at all in the road world? OK, so brake/frame design might preclude it in some cases, and perhaps it's a weight thing, but surely it makes sense for many/most bikes?