Montreal had a baseball team in the National League for many years. It began in 1969 and it ended in 2004. The team moved to Washington D.C. and became known as the Washington Nationals. In 1995, attendance fell during their games and it continued for about five years. From 2000 to 2004 when they relocated, Montreal Expos and their franchise went downhill. It does seem that there are interested investors that would like to start another baseball team there. They also have the citizens and government supporting them.
So, it seems that it is only a matter of a few years, if that, to start a team in this large Canadian city. However, only time will tell to see if Montreal gets their team back.