You still need to call it whenever you show/hide/resize something other than a bottom panel (e.g. the status bar, a ModalBar at top, or some custom UI like RWDY or SVG Preview)... _or_ whenever you show/hide a bottom panel with raw jQuery calls rather than using Resizer or Panel APIs.

Eventually it'd be nice to move more of those cases over to clean PanelManager APIs -- eventually we could even deprecate resizeEditor()!  But to minimize disruption, that hasn't been done yet.

I'll clarify the docs on this.