Thanks for the reply!Welcome to this thread!
Why file moved? ... Because files move around offices depending on work load all the time.
Why no updat? ... Because IRCC doesn't really care about updates. And if you meant why they didn't update you on file move then they never do. Your file may move back to Calgary or to a different office again and they won't tell you that.
Given your AOR and if your file stays in Montreal brace yourself for a long(er) wait. Montreal is still processing Nov / Dec applications from 2018. And based on recent trend it takes a minimum of 7/8 months to process files. It may change in future but for now be prepared to wait till Oct.
Hope for the best!