This problem of late announcements also applies to travelers that don't need visa. Recently, a major CS conference announced accepted papers two months before the conference date. Since it was a large federated conference located in a tourist destination in Florida, in the middle of the season, traveling from Europe was particularly expensive when buying tickets on a short notice.
And there's the additional downside that it was too late to apply to workshops and posters at co-located conferences. Many major conferences take place in the US, which means that traveling just for a workshop paper might not be feasible for researchers based outside of the US due to university policies and budget constraints. Thus, it's a good opportunity to participate and publish additional results while you are already there.
And there's the additional downside that it was too late to apply to workshops and posters at co-located conferences. Many major conferences take place in the US, which means that traveling just for a workshop paper might not be feasible for researchers based outside of the US due to university policies and budget constraints. Thus, it's a good opportunity to participate and publish additional results while you are already there.