The 19-year-old was eligible to take part in the tournament, but will instead remain with his NHL club.
"(Horvat) is a solid two-way player, strong in the faceoff circle and displays a maturity beyond his years," Canucks general manager Jim Benning said in a release. "We're very pleased with Bo's play and look forward to watching him develop as an NHL player."
Horvat has one goal and four assists while averaging just over ten minutes of ice time in 17 games with Vancouver this season.
The London, Ont., native played for Canada at last year's world juniors, registering three points in seven games.
Among the other Canadian junior-age players not being released by their teams are Florida Panthers defenceman Aaron Ekblad and Tampa Bay Lightning forward Jonathan Drouin.
The New York Rangers allowed forward Anthony Duclair to join Canada's roster for this year's tournament.