Seems like the Met would have made sure she could be heard before they hired her. I doubt they would mic one singer. Or any!!! It's the Met, that's their thing, singing without amplification. Here's what the NYTimes wrote about Fledermaus:
"In rehearsals, Mr. Sams has taken special care rehearsing one of the trickiest things about “Fledermaus” — all those scenes without music.
Those stretches can leave opera singers feeling exposed, especially in a house the size of the Met. This year, the Met plans to amplify the dialogue to make sure it can be heard. (Officials stress that they will not amplify any of the singing, which is verboten in serious opera houses.)"
https://mobile.nytimes.com/2013/12/29/arts/music/jeremy-sams-directs-die-fledermaus-at-the-met.html I would think it would be really confusing to sing without amplification loud enough so that 3800 people could hear you and then to speak into a microphone.
She just tweeted about it:
"Now I can shout it from the mountain tops...a dream come true! The Merry Widow
@MetOpera https://www.broadwayworld.com/article/Kelli-OHara-Susan-Stroman-to-Make-Met-Opera-Debuts-in-THE-MERRY-WIDOW-on-New-Years-Eve-20140212# …"
Didn't she major in opera or am I imagining that?
Kelli O'Hara's excited tweet about Met Opera debut
Updated On: 2/12/14 at 08:59 PM