I'm not sure if this is a bug, or a feature request. Anyway...
The single most annoying thing (for me) about using the Cadabra gui interface is that when I create a new cell with alt+Up or alt-Down, the cursor remains in the old cell and I start typing, thinking I'm typing into the new cell, but I'm actually over-typing or corrupting the original cell.
It seems to me that if the user creates a new cell the overwhelmingly likely next activity would be to type something into that new cell. Hence, auto-refocusing the cursor into the new cell seems the most helpful thing to do.