Trevor Moore, was considered a young and up and coming prospect with the Maple Leafs when he was traded to the Los Angeles Kings. Moore was part of the package sent to the Kings in exchange for Jack Campbell. At the time Moore couldn't crack the Leafs lineup as a regular and despite doing everything the franchise asked of him, he couldn't stick on the main roster.
While most teams celebrate this sort of thing it's clear the current Maple Leafs core, led by John Tavares doesn't have that sort of comradery. Hopefully this is something the new additions to the Maple Leafs can repair, because the culture of the team needs an overhaul.