It was rehearsals before the show opened.

Looks like a press sneak peek.

@@jessical.538 It's definitely not Tony Rehearsal. Jerry Zaks wouldn't be explaining what was happening in the scene if the show had been running, and everyone already knew.

It’s a pre-show rehearsal. The reason they perform a cut version is to keep it as a sneak peek performance, that way they’re getting publicity but aren’t releasing the full content (especially because this is one of the biggest numbers from the show) almost every Broadway show does it

It’s pre broadway rehearsals.