I always thought that was how it was supposed to work. The frozen MIDI is "frozen" so therefore unaffected by any edits, including ripple edits.
Whenever I select "Ripple Edit All Tracks", I unfreeze everything, move the tracks and then re-freeze the tracks.
It's a bit of a hassle, but for me it's worth having Ripple Edit. It still saves me a lot of time and work.