It's not impossible for them to fit a coaster near Bayside stadium, I just don't know if they're interested in that area for this attraction. The Wild Arctic, Shamu, Sesame area has always kind of been void of a cohesive theme, and I would imagine they would see that area as potential future for a Sesame expansion. Obviously we don't know the ride theme yet, but I doubt it is anything relevant to any of those attractions. Additionally that area doesn't really need a new ride at the moment, with Sesame, Infinity Falls, Wild Arctic, Shamu and Mako in close proximity, it's likely that it will be a popular section of the park for the coming years.
I posted something similar a few pages back, but there is plenty of space on the north side for a decent length launch coaster. Remove the clearance store and the hot dog stand and relocate a parking lot behind the scenes and you open up several acres for new development in what used to appear as a landlocked area.
This would make for a perfect area for a Wavebreaker launch coaster or anything relavant to Key West/Rescue area, heck could be a sea turtle themed ride akin to Crush in Finding Nemo. What's nice about this area is that it's very unobtrusive. Most of the ride would take place in areas not visible to the public, yet, the ride would be visible from several vantage points as you're approaching the park and near the entrance that could build excitement and anticipation!
The green area is where I believe the new headquarters may be so possible that some of those buildings may even be removed opening up more space. Also, this isn't a ride layout I've drawn up, more of a path that it could take!
Overall, I think it's awesome just how much has occurred at SeaWorld in the last 10 years. Manta, Mako, Infinity Falls, Antarctica, Turtle Trek, Sesame, not even mentioning all of the other minor additions and new shows. The park is almost unrecognizable if we were to go back! It's nice to see they have a commitment to new attractions and of all of the Orlando parks, I would argue has changed the most in the past decade.