It's public record. Wasn't hard to find. "The Bills shall not sell, assign or otherwise transfer the team to any person who to the Bills knowledge, has an intention to relocate, transfer or otherwise move the team during the non relocation period to a location other than the stadium". So they can't be sold to a Toronto group who intends to move them. End of story. Any such deal would be cause for an injunction and the NFL knows this which is why it will be a local ownership group.