If you search Nikki Abissi up on Google, the first result after her own website is her bio on the Pershing's Own website, which probably caused the confusion.
Nikki did indeed get offered a trial, but she's not with Pershing's Own. From what I heard Connor Rowe, of the Coast Guard Band, was offered another trial. Steven Harmon won the horn audition.
I’m told Nikki Abissi was offered a trial for the trombone position