The 25-year-old singer has had a difficult few months, following the tragic death of her ex-boyfriend Mac Miller in September and her recent split from "Saturday Night Live" star fiance Pete, and has cancelled various appearances - including a performance at a cancer benefit over the weekend (October 13-14).
However, Ariana took to Instagram on Monday to promise her devoted followers she was never going to give up a chance to appear in the NBC special, which is celebrating the 15th anniversary of musical "Wicked" debuting on Broadway.
Sharing a script page featuring lyrics from the tune "The Wizard and I", Ariana wrote: "honoured to be included in this celebration of 15 years of my favourite musical of all time. wouldn't miss it for the whole universe."
Her post came as her brother Frankie Grande offered his support in the wake of her relationship breakdown. Sharing a video on his Instagram Story, Frankie told his sibling, "Good morning to my beautiful, beautiful sister. I love you so much and you're with me right now in Iceland."
He then began singing along to Ariana's track "Breathin'", crooning "You know you gotta keep, keep on breathing", before adding to the singer, "That's true."
Despite Ariana and Pete calling time on their romance, it's been reported that the former couple ended things amicably and are still planning on hanging out together.
"Their engagement is off, but they still plan on spending time together," a source told People. "It's not like they split and never plan on seeing each other again. They just decided to slow things down."