That's... weird.

I *could* imagine the bride being stressed about planning a big wedding abroad and then a big to-do locally after--and so waiting to set in stone the local event only once the abroad wedding is done.
Though that is inconsiderate/dismissive of everyone's time/relationship.

However--from the other comments you've answered--the event abroad was a *small* group. Seemingly relaxed.
I don't see a reason of they're having waited due to stress.

I wonder the reasoning for the smaller wedding. One abroad can be expensive. Do you know whether it was their decision or the decision of whoever offered/paid for it (if not them) ?