They should last till the entirety of this patch. Usually around a month.
Concierge generally get a mail telling when a concept sale will end and notifying of the extension of the sale for concierge (though I don't recall having received it for the expanse). So a concierge can let you know here later when this happen.
Scorpius sale might end without notification before Mule and Legionnaire as it is not a concept or direct to flight ready release.
Well, I should know when concierge find out, but that involves me making the effort\remembering to check those RSI emails...
Looks like I'll be grabbing a few more event CCU's once they all return to store - I really wish you could buy multiples of a CCU (as well as multiple of a CCU to same end ship from different starting ships) at the same time, not have to put individual orders for every $5 CCU - I'll be aiming for quite a few Vulture ones, as well as a couple of others.
As a side note: Is it likely that the SRV, Vulcan, Apollo, or Liberator will appear on\before IAE this year (I'll be grabbing a personal "last mile" CCU for the ones I don't have, just wondering if it's worth grabbing more for chains, or hold off until later for them)?