An early curtain that afternoon should be a pretty good indication that they expect the cast to perform that day.
In general (and to be fair, this is completely anecdotal based on my experiences), I have found that most nominees do in fact perform their matinees that day, as they often talk about the rush to get ready for the awards in the (relatively) brief amount of time between the end of their matinee and the beginning of the telecast (compared to say, the Oscars, which seems to be an all day affair in terms of preparation and such).
Updated On: 5/12/18 at 02:06 AM