I pointed out before that TRON, while a new build, unfortunately has to also make up for the lost capacity of Stitch closing without replacement.
To give another example of MK adding rides, but not really, "the largest expansion in Magic Kingdom history" resulted in Fantasyland having the same number of rides it did in 1971 because they decided to get rid of Snow White's Scary Adventures entirely instead of keeping or making it another dark ride.
I don't know what it is with this park and never really gaining rides. The last time it truly did was when Splash opened in 1992, but then they closed 20,000 Leagues 2 years later. Then they added Barnstomer in 1996, but removed the Skyway in 1999. Magic Carpets opened in 2001, but the same year they stop running the Keelboats. It's a cycle that never ends.