Pretty sure any changes would not be to increase capacity. At the very least, they will simply widen out the "seats" to make more room by having fewer "seats". If they find a way to do a major renovation it would almost assuredly include more suites like in north stadium and - again - fewer total seats. Other than wider seats, they are definitely looking at ways to increase and improve access to restroom and concession facilities.
I'm actually kind of surprised they didn't widen some of the seats in South Stadium last year like they did in North Stadium two years ago. Haven't heard anything for this year either though it could still come. The lack of doing that despite a decent amount of talk about it is the only reason I think they might still be trying to find some way to do a more-major renovation.