The election official maintains a broad mandate to maintain order. They can ask someone to leave. The directive will be for them to call the police.
The amendment removes the use of force to ask people to leave, and also arrest without a warrant. It may pose problems delivering, for example, a charter caution, which is a complex affair. Not all election officers will feel comfortable doing that. They won't have the specialized training to do that. The amendment reflects the reality that the job is for the police officers to remove people, in Elections Canada's mind.