Every performance through the first of May is now on TDF, and other discounts including TKTS are available. Anyone wanting to see the show should be able to find a more affordable ticket.
My guess from the posts: Ms. Kulakango has had a cold/equivalent and will return to the full 8. Elsewhere, I've heard speculation that she will use the standby as alternate. Not verified.
It's important that it's being recorded. As noted above, this show likely has a full life elsewhere, particularly colleges. Recorded scores matter in promoting subsidiary rights. And for now, a music drop might well help it on Broadway. I went early because I liked the Chicago clips I'd heard on YouTube.
"I'm a comedian, but in my spare time, things bother me." Garry Shandling