Don't have a 2014 or older to compare, but I can tell you my 2015 front calipers are fed by the same brake line, with a 'Y' between the forks. And similarly, just one brake line to the rear caliper. So apparently there was a hardware change too, if older ones were not like that. I HATE not having 100% front power with the lever, like Honda does. At least now, the brakes are linked electronically only. But not ideally, nor fully, like on modern BMW bikes, where the front lever provides 100% front & rear braking power (including a proportioning valve), and the rear only the rear.
The Connie has 100% FRONT braking power with the lever, but not 100% at the back. I think it's 50%. And I doubt it's 'intelligent' enough to be proportioning, but don't really need that on a sport-touring bike IMO, especially if riding solo. But it might have it. Somebody with a passenger can play with the brakes and find out easily. Solo, I feel no difference whatsoever using both brakes (as expected), from just the front... which is what I always do. I've been looking everywhere for specific info on the brakes, but just couldn't find ANYTHING. Anyway, the pedal has 100% power for the rear, and I believe 20 or 40% at the front, depending on linking setting (2 available- low and high). So just the rear pedal would be dangerous folks, as braking distances would be tremendously longer. As you should know, the great majority of braking is at the front, and that's why you have 8 pistons and 2 big a$$ rotors, vs 1 or 2 pistons and a puny rotor. Besides, by only using the front brake, in case of an emergency in a non-ABS bike, you'd be much less likely to inadvertently lock-up the rear wheel and end up on the ground. Believe me, modulating the front brake alone is enough even for an experienced rider. And on bikes with linked brakes, makes no difference to use the rear pedal, so no downside to just use the front lever. But to each his own. But yes, with ABS, you can do whatever you want... but just make sure you're capable of invoking ABS (100% braking power) with the front lever, or you'd be wasting precious real estate in an emergency. Practice folks.