Yes, I know...hard to figure why...

But then, why not worldwide same-date release ?

Maybe :
It takes a lot of money and time to organise a "physical" release of that magnitude...You have to find a place to rent, hire people ( girls,girls girls), secutity, management, airplane tickets, hotels, catering, journalists, media, etc.
So I would say you have to prepare, hum...lets say..4 months in advance ?
So just before everything went wrong ? They were so sure at that moment that everything was tight and slick...What could go wrong ?
So they had to keep on going...I am pretty sure that without a 'physical" release, they would have posponed for few months...
So we have later dates everywhere else..But it would have been hard to justify months of delay..They pushed has long as "reasonnable"...

And that is IMHO !

Salute !