If I understand your question correctly, changing the rough-in would mean moving the centerline of the flange 2" closer to the wall. The flange is sitting on top of a waste pipe that is turned upwards to meet the floor. In older homes, this is often made of a heavy metal, and, of course, the hole in the floor and subfloor for that pipe has already been cut for a pipe whose centerline is 14" from the finished wall. It's certainly doable in the sense that any floor can be torn up and any plumbing changed and/or replaced. But I believe they will tell you that it's usually a significant amount of professional work and a significant expense. (But I don't presume to speak for the pros who know what this entails.)
A more cost-efficient alternative, if it works for you, is the Toto-exclusive Unifit Adapter. The idea behind it is that the toilet will sit in the same position from the rear wall regardless of whether the rough-in is 10, 12 or 14 inches. A male fitting on the toilet, facing down, is slid into a female fitting on the one end of the Unifit, pointing up, which fittings are near the wall. The Unifit, depending on its size, "reaches forward" so that its other end will cover and attach to a flange that is positioned with its centerline either 10, 12, or 14 inches from the wall. The toilet's always going to install in the same spot; the only difference is how far forward the Unifit will reach. It's a neat idea, and like all things Toto, they have tweaked it over the years to improve it. (You actually install the Unifit first, and then mount the toilet on it, but I'm hoping that the "reaching forward" idea will help you visualize how it works.)
I took a few minutes to look at the spec sheets for the various Totos that use the Unifit. As Jim says, on the 14" rough, the toilets vary from 28" even to 28-7/16" for the toilet plus 3/4" to get the total distance from the finished wall to the front of the toilet. If your flange is a smidge less than 14" from the finished wall, then the total distance will be less; a smidge more then a smidge more. Some of the current models that use the Unifit are:
Carlyle II (I have this...love it): MS614114cefg nominally 3/4" from wall plus 28 5/16" toilet length, only 16 1/2" wide "tank" (it's a one-piece).
Vespin II (two-piece): CST474CEFG, (exact same specs as above, including tank width)
Eco Soiree (one piece) MS964214CEFG 28 1/8" length, 17 3/4" wide lid (lid is wider than tank)
Legato (one piece) MS624214CEFG 28-7/16" length, 15-13/16" china width (plus 1.5" trip lever on left)
Aimes (one piece) MS626214CEFG, (same dimensions as Legato)
Carolina II (one piece) MS644114CEFG, 28-5/16" length, 17.5" incl trip lever width
[old] Carolina (one-piece discontinued) MS884114 only 28" length, only 16.5" wide, 1.6gpf old Power Gravity flush -- some still out there apparently
Lloyd MS934214EF (one-piece) 28-1/8", 18-5/8 wide, E-Max 1.28gpf flush (no double-cyclone) [also SF for G-max flush] [also MS934304EF or SF, same toilet with different seat]
Guinevere MS974224CEFG (one-piece) 28-1/4"length, 18" wide incl trip lever
https://terrylove.com/pdf/ms974224cefg.pdf
Hope this helps...