The park didn't reveal much about the reasoning behind the ride's retirement, or exactly what the plans are for the ride's eventual removal or replacement:
“No decisions have been made about what lies ahead for Gwazi or for the future plans of that area of Busch Gardens,” said Park President Jim Dean. “But, we are always looking for ways to enhance guests’ experiences, so stay tuned for more news.”
Gwazi first opened in 1999, and will have operated just over 15 and a half years when it closes next month. The ride has only operated one track ("Lion") for some time now, so the last opportunity to ride the "Tiger" side of the attraction was actually in 2012.
This will also mark what could be argued as the first removal of a Great Coasters International ride, though the Ozark Wildcat last operated in 2008. That all depends on when Gwazi is taken down, and what eventually happens to the Ozark Wildcat, I suppose.