It’s been a caucus for years, I’ve gone to them. I don’t like it, hope they change back to a primary vote, but “they” didn’t cancel anything.
http://www.denverpost.com/2015/08/25/colorado-republicans-cancel-presidential-vote-at-2016-caucus/
Last August when the national GOP said delegates had to be apportioned according to primary voting results, the Colorado GOP on auto-suck to Cruz cancelled the planned primary.
the Democrats actually got to vote here. The GOP did not.