According to Sports Illustrated's David Alter, the Leafs have games scheduled to take place in Toronto at Scotiabank Arena on April 27th and May 1st. The problem is that there are already two events scheduled to take place on those dates, including a concert by hard rock touring artists "Distrubed" on May 1st on what would be the evening of Game 7, if the series gets that far.
With the Leafs and Raptors having contracts with Scotiabank Arena, they will very likely have priority on any playoff dates, which means the other two events will need to be postponed. This certainly isn't the first time a team has had a scheduling conflict in their home arena and I'm sure it won't be the last.