Talk:65th Episode Rule/@comment-26618197-20151008124235/@comment-24155515-20180207182011

And, according to some sources, could have had more. (They pitched a series that would let other people involved in the show continue working on it. Disney said no, then came back later with the same basic series, moved to Miami or something with Selena Gomez riding on it and a lower credit for them. They said no.) That could have theoretically bumped the Suite Life franchise all the way up to as much as nine or ten seasons.

I think the 4 season thing is a practical limit rather than an actual "rule". Fourth season is about where children's shows' ratings start to taper off, it's where shows may jump the shark or lower in quality (even SLOZAC lowered in quality in its third season and they even got a spinoff), and it's where someone who may have been of an age to relate to the target audience of the channel when the show started may be old enough to have started to "age out" and not be as big of a draw to new (read: younger) viewers.