Sort of both. The way we originally had it working, the shooter would try to find a layup as close to the direction the RS was held... so essentially, doing what you're asking for (letting you pick the finish direction.)
But in our play tests, a great number of people pushed toward the basket to get a regular layup, expecting the shooter to automatically avoid defenders. The problem is, most people are inaccurate with their stick throws, so even though they thought they were pushing slightly to the left of the rim to finish on that side, they were actually aiming toward the right and putting the ball right into the defense. So my shot system engineer spent a great deal of time working on shot selection algorithms to pick the best layup given the shooter's drive angle and defender proximity. This work greatly benefited shot button users btw. So after much back and forth, we made the decision to use the auto-shot selection code instead of the literal follow the stick method. In 5-on-5 gameplay, we just found that it was beneficial to more users.
Having said that, I'm working with my engineer to try and bring the finish hand selection back. It will definitely be there in the NextGen version and hopefully make it into the current gen patch as well.