@bruhbsn I just called the placement office to ask. She said that the more information we provide, the better they can place us where we'd more like to be. So if you'd rather have your second sub-specialty in your second choice than your last sub-specialty in your first choice, then that would be a great thing to list in the additional comments section. But she did seem to think that ranking every single specialty might be better in terms of making placement easier for them.
I also asked if she knew how the finalists were selected - GPA? essay? She said she wasn't sure, but she thinks that they really just look at them holistically. That they've already gone over things, and with the final 100, they just review our apps more in depth and pay even closer attention to everything.
She was seriously so stoked about the final 100 (not sure if it's actually 100 people or not, but that's what everyone seems to call it). She said it's such a huge accomplishment and that she wishes us all the very best! I thought I'd pass that along because regardless of what happens, it truly is an honor to have gotten this far!!!