Assuming when you say interfaces, you mean User interfaces...For any VI, if you add, remove, or change the inputs &/or outputs (Controls &/or Indicators) you will typically have to re-connect the terminals of that VI, or at least the changed ones. This will ripple down the line, and all other VIs that 'call' that VI will need equally updated since the original terminal setup has changed.
Sometimes, this can be prevented or minimized if the orignal terminal setup allowed for extra inputs & outputs. However, there is no auto-relink or auto-update for VIs that call other VIs with changed terminals, mainly because those VIs really don't know what changes apply to them.
Understanding all the requirements before coding will be the best prevention, but obviously is easier
to say than do.
Good Luck with it, Doug