The revival took decades, what's a few months? I would imagine that summer is not generally the best time to release an album, even a musical. On the other hand, they clearly know a sliver of an audience is sitting by the computer, ready to buy this one. I'll be curious to see how they cut the material. In the revisal, a lot more of the music seemed integrated into the dialogue ("The World According to Chris" and the prom sequence for example). Will we get 70 minutes of the show, or more of a DREAMGIRLS type of recording, i.e. re-configured numbers. Unlike the original, there's also a fair amount of cursing built into the high school scenes, and I'd imagine they'd prefer the album not have the lyric warning. So they may still be working on the album, making creative decisions. Though the music is generally cut and set prior to recording, a fair amount of wiggle room exists.
"I'm a comedian, but in my spare time, things bother me." Garry Shandling