I can't speak much about your technical question, but I can provide some context as someone who's used eBird heavily for almost a decade. eBird does go down for

I can't speak much about your technical question, but I can provide some context as someone who's used eBird heavily for almost a decade. eBird does go down for maintenance (both planned and unplanned) every few months, but to my memory this is by far the longest maintenance window they've ever done and it has obviously been telegraphed months in advance and almost certainly planned for a time when the site saw lower usage (Mid November is the closest thing you'll likely get to a worldwide low point in bird migration). They haven't made any announcements about what they're doing during this window, but I would expect it's a pretty monumental change or several large changes they've been holding off on for a long time. It's also worth noting that this is a fairly small non-profit operation. It might be possible to do what they're doing without taking the site offline, but perhaps it would require taking their devs off other projects for several months to make it happen?