An interview request is not abnormal on many circumstances. Interviews are common for couples who haven’t spent much time together in person and don’t have a long dating history. This is often the case when there has been an arranged marriage and the spouse has flown to their home country, gotten married and returned to Canada soon after their marriage. If there are concerns about the validity of the relationship and interview can also be requested. For example if there is a large difference in age between spouses and/or other red flags where there are concerns that the relationship may not be genuine and the goal is purely immigration. For Pakistani applicants many are offered an interview in Pakistan or the option to travel to London and be interviewed at an earlier date. Many don’t have a visa to go to London and there is a significant cost to fly to the UK to complete the interview a few months earlier. New offices are scheduled to open in Pakistan so you may get lucky and there may be a person who does interviews full-time out of Pakistan in the near future.