No matter what, I think, psychologically speakng, some pax would feel unconfortable about flying after two failed take-offs.
Honouring those pax's wishes to deplane might cause some delay, but from a management pov, wouldn't it also show the carrier's confidence in its operation by allowing pax to deplane, as it shows that they really do have their guest and safety in mind, rather than pure business and carefully-calculated cost-benefit analysis? I mean, such anaylysis is great for the business, but perhaps not the majority of the pax would put the profitability of the airline berfore their own sense of security; indeed, why should they care?
Maybe they should've deplane those who wished to, informing them of the subsequent significance of their choice, ie, potential flight change penalty, have to waitlist for the next flight, and provide all pax who chose to stick with their flight vouchers for the potential concern the event has brought to the pax. I mean, of course legally they might not required to do that, but it'd be good business, no? JAL offered several bonus mileage campaigns just to apologise to their frequent flyers and new pax for the bankfruptcy mess causing concerns and failing the trust their pax placed in JAL in the first place, maybe CX should learn from it and caugh up some bonus-miles or coupons/vouchers for future flights as well?
I wonder, if CX offered any "compensation" or "good well gestures" for the incident at all?