The following season, with the 2020–21 OHL season suspended due to the pandemic, McTavish returned to Switzerland, though he was unable to get a work visa until he turned 18 years old, eventually joining second division side EHC Olten on January 29, 2021,[2] where he would play 13 games before returning home to play in the under-18 World Championships, where he served as captain and scored eleven points in seven games as Canada won the gold medal.

[6] He was initially scheduled to not play in the team's opening day game against the Winnipeg Jets but was added to the lineup just hours before the contest.

He was assigned to the Ducks' American Hockey League (AHL) affiliate, the San Diego Gulls, on a conditioning loan on October 28.

[9] McTavish appeared in five games with the Petes, posting six goals and seven points before he was traded to contending club, the Hamilton Bulldogs, in exchange for two prospects and six draft selections on January 9, 2022.

[12] Shortly afterward, McTavish was selected to play for Canada senior team at the 2022 Winter Olympics, the NHL having declined to allow its players to take part.

[16] When the International Ice Hockey Federation (IIHF) revived the cancelled 2022 World Junior Championships in August 2022, McTavish was again on the roster, and this time was named captain of the team in the absence of Kaiden Guhle.

[18] Canada advanced to the gold medal game against Finland junior team, where McTavish had his most significant moment of the tournament in overtime, using his stick to knock Finnish defenceman Topi Niemelä's potential game-winning shot out of midair onto the goal line, preventing a loss.