It is not known how. Your file can be "randomly" sent to Calgary office or somewhere else. There are way too many factors and variables. You can only order GCMS notes and see what your Primary Processing office and Secondary Processing office at the time of ordering GCMS notes is.
For example this is how it shows in my GCMS notes:
You can also call IRCC and ask about your Primary and Secondary processing offices.
My guess, is that North and West Vancouver would belong to Vancouver Citizenship office. However, I also know that Surrey has its own. It depends on the case load and other factors. I would also guess, that in your case, if you are moving to Vancouver from North Vancouver, you are more likely remain with the same processing office. However, reporting a change of address may or may not delay your processing time. It will also may or may not trigger sending your application to another secondary processing office.
