On March 27, 2019, Fabbro signed a three-year, entry-level contract with the Nashville Predators. He made his NHL debut a few days later on March 30, in a 5–2 loss to the Columbus Blue Jackets and recorded his first career NHL goal on April 9, 2019.
On April 29, 2019, following his first playoff experience with the Predators, Fabbro was named to the Team Canada roster for the 2019 IIHF World Championship held in Slovakia. Fabbro helped Canada progress through to the playoff rounds before losing the final to Finland to finish with the Silver Medal on May 26, 2019. He finished the tournament posting 1 goal and 3 points from the blueline in 9 games.