ErmengardeStopSniveling said: "What happens if an understudy for Joaquina Kalukango or Noah Reid (or anyone) performs on Opening Night and/or press performances due to Covid? Is the understudy considered the lead of the show for awards purposes since they technically performedonOpening Night? Is there a policy in place, or will the League have to make clarifications this spring?
(Obviously if the sick person in question is Billy Crystal or Daniel Craig, they just cancel the show; but if the actor isn't selling tickets and they have a half-rehearsed understudy, then the show must go on)"
I would assume the nominating committee would either take it upon themselves to state that the actual performer is eligible and not the understudy, or the producers would file a petition and the committee would grant it without hesitating. Of course, if I'm not mistaken, most of the rule language centers around what the billing is on the title page of the Playbill as of opening night, in which case the main performer is still billed there, even if an understudy happens to go on for opening night, so it may not be an issue at all.
Back to the question, though she wasn't nominated for a Tony, Joan Jett does not appear on the recording of the Rocky Horror revival due to contractual issues between her record label at the time and the company (RCA, I think?) that was producing the cast recording.
On The Secret Garden cast recording, there are two actors singing Colin's songs. John Babcock, who opened the show, does all of the "book" tracks, as well as "Round Shouldered Man," but his understudy, Joel E. Chaiken, sings "Come to My Garden/Lift Me Up" with Rebecca Luker. I have heard it was because by the time they recorded it John Babcock's voice was already beginning to change and had either already left the show, or would be leaving it soon, and they felt that it would be better to have Joel sing "Lift Me Up" since that had a higher range than "Round Shouldered Man."