Leafs have large enough fanbase within Toronto that they could sell those tickets behind the benches even as individual tickets for the game.
Ideally, you want something like: If a firm wants to renew platinums, offer them gondolas or suites instead (I know they are limited). If they want to transfer membership to individual name (instead of firm),they can retain it. So, the load of paying from own bank account, instead of a firm's accountsheet will force people to transfer season license. Even if someone ends up cancelling platinums, there will be real fans who would like to buy them as individuals.
Providing financial support is not the only thing as a fan. You want to support the team by cheering once you are in the arena. So many times we have heard of fans being asked to shutup while cheering for Leafs in the lower bowl.
/rant