On July 1, 2017, having left the Blue Jackets as a free agent, Tynan agreed to a two-year, two-way contract with expansion club, the Vegas Golden Knights.[5] After attending the Golden Knights inaugural training camp, Tynan was assigned for the duration of the 2017–18 season to the AHL to play with affiliate, the Chicago Wolves. Selected as an alternate captain, he was used in a top-line role. Tynan placed second to Teemu Pulkkinen in scoring with Chicago, posting 15 goals and 60 points in 70 games.
In the following 2018–19 season, Tynan continued as a staple of the Wolves attack, producing at a point-per-game through 71 regular season appearances and collecting a league leading 59 assists. He added 2 goals and 13 points in 22 post-season games, helping the Chicago Wolves to the Calder Cup Finals, before losing to the Charlotte Checkers.
As a free agent from the Golden Knights, Tynan agreed to one-year, two-way $700,000 contract with the Colorado Avalanche on July 1, 2019.[6] After attending his first training camp with the Avalanche, Tynan was among the last cuts re-assigned to begin the 2019–20 season with AHL affiliate, the Colorado Eagles.[7] Signed to add offensive depth to the organization, Tynan led the Eagles to start the campaign posting 12 points in 10 games before he was recalled to the NHL by Avalanche on November 6, 2019.[8] Returning to the NHL for the first time since March 2017, Tynan re-united with head coach Jared Bednar from their Calder Cup winning tenure with the Cleveland Monsters. He made his Avalanche debut in a 9–4 victory over the Nashville Predators on November 7, 2019.[9]
At the conclusion of his contract with the Avalanche, Tynan left as a free agent to sign a one-year, two-way contract with the Los Angeles Kings on July 28, 2021.[10]
Tynan remained with the Kings for three seasons, primarily playing with the Kings’ AHL affiliate, the Ontario Reign, where he led the club in scoring every year. He recorded a team-best 57 assists and 66 points in 71 games during the 2023–24 campaign and paced the AHL in assists for the third straight season.
Following two years as the Reign captain, Tynan left the Kings as a free agent and returned to the Colorado Avalanche organization after in signing a one-year, two-way contract on July 1, 2024.[11]