As it's been explained to me (a long, long way away now- or 'a safe distance'
)
Airspace no longer 'closes'- the workload is merely 'managed'. i.e. Whereas previously, you might have a sector go TIBA due to not enough staff, NOW they leave that sector open, combine it with another sector (sometimes with someone not rated on that sector), but reduce the flow rate dramatically. Tadaahhh! NO TIBA. The airlines still cop a rogering (delays) due to AsA's cost shifting, but there are more smoke and mirrors so that it doesn't end up in the papers. No more "please explains". It just appears as a 'traffic delay'.
I tell you, managers are worth every penny.