To me it’s clear that people should have a chance to see what’s there before they have to pick something. It’s not like we are under a huge time crunch to vacate the building or something.
There is literally no way to look at all the corals before having to pick in the first round, especially in the larger open swap.
The only reason I could see to not give enough time to preview for everyone, is to intentionally give an advantage to the bonus round members and members volunteering to screen and setup the corals. After all, those are the members contributing the most to the swap. But if that is the reasoning, we should be open about it.