Is there any doubt that would it be any other franchise Koivu's number would be retired?
1993 serves as something of a dividing line for Montreal Canadiens history. Prior to that, dominant team, constant threat to win Stanley Cups, legendary players. After that, sometimes good, sometimes mediocre club that has rarely set itself apart from the rest of the pack, hampered for years by middling to bad management.
In that post-1993 period, Koivu stands above all for what he means to the Canadiens. By modern-day NHL standards, his number absolutely would be retired.
Oh captain, my captain, it was so good to see you wearing the CH again last night.